Materiały źródłowe

• #1 Miscarriage | Pathology, Symptoms & Treatment | Britannica

  https://www.britannica.com/science/miscarriage

  miscarriage, spontaneous expulsion of the embryo or fetus from the uterus before the 20th week of pregnancy, prior to the conceptus having developed sufficiently to live without maternal support. An estimated 10 to 25 percent of recognized pregnancies are lost as a result of miscarriage, with the risk of loss being highest in the first six weeks of pregnancy. […] The most common cause, accounting for more than 60 percent of miscarriages, is an inherited defect in the fetus, which might result in a deformed or otherwise abnormal child. An acute infectious disease may play a role in causing some miscarriages, particularly if it reduces the oxygen supply to the fetus. Certain uterine tumours or other uterine abnormalities also may induce a miscarriage. Death of the fetus stemming from external trauma or from knotting of the umbilical cord is another cause of miscarriage.

• #2 Miscarriage: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/001488.htm

  A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. […] Most miscarriages are caused by chromosome problems that make it impossible for the fetus to develop. […] Other possible causes of miscarriage may include: Drug or alcohol use, Blood clotting disorders, Exposure to environmental toxins, Hormone problems, Infection, Obesity, Physical problems with the mother’s reproductive organs, Problem with the body’s immune response, Serious body-wide (systemic) diseases in the mother (such as uncontrolled diabetes), Smoking. […] Around half of all fertilized eggs die and are lost (aborted) spontaneously, usually before the woman knows she is pregnant. […] The risk for miscarriage is higher: In women who are older — The risk increases after 30 years of age and becomes even greater between 35 and 40 years, and is highest after age 40. […] Miscarriages that are caused by systemic diseases can be prevented by detecting and treating the disease before pregnancy occurs. […] Taking a prenatal vitamin or folic acid supplement before you become pregnant can greatly lower the chances of miscarriage and certain birth defects.

• #3 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Recurrent pregnancy loss is a complex health challenge with no universally accepted definition. […] The exact etiology of recurrent pregnancy loss remains questionable; thus, it is considered a polyetiological and multifactorial condition with many modifiable and non-modifiable factors involved. […] The relevance of various factors and their proposed roles in recurrent pregnancy loss pathogenesis remains a matter of discussion. […] Studies on etiology and risk factors for recurrent pregnancy loss, especially idiopathic, should be continued. […] RPL is a polyetiological condition, and the reason is often unknown. Several factors have been suggested to contribute to RPL pathogenesis, including maternal age, endocrine diseases, uterine morphological pathologies, chromosomal abnormalities, thrombophilia, infectious agents, and autoimmune disorders.

• #4 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Nevertheless, in approximately 50–75% of RPL cases, the exact cause is not clearly identified and, therefore, remains unexplained (idiopathic). […] The contribution of uterine structural anomalies to the etiology of RPL was reported in several studies and found to be present in about 7–28% of women with RPL compared with 4–7% of women in the general population. […] The most common congenital uterine anomalies include septate uteri, arcuate, and bicorporal uteri. […] Among patients with congenital uterine defects, women with a septate uteri have the highest incidence of recurrent miscarriage. […] A lot has been reported on the role of genetic factors in RPL, as chromosomal abnormalities are one of the significant causes of miscarriage in the first trimester of pregnancy. […] Genetic risk factors, including abnormal embryonic genotypes and parental chromosomal rearrangements, could be a background for more than 50% of RPL cases.

• #5 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #6 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #7 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #8 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #9 1st trimester miscarriage: four decades of study – Hardy – Translational Pediatrics

  https://tp.amegroups.org/article/view/6176/7081

  The most common cause of first trimester spontaneous loss is sporadic chromosomal error. They may be errors of meiosis, mitosis, or fertilization. Maternal meiotic errors had long been suspected by the relationship between elevated maternal age and increased occurrence of such conditions as Down syndrome (trisomy 21), Edward syndrome (trisomy 18), and Patau syndrome (trisomy 13). […] The types of cytogenetic alteration are constant across all published series. They include: monosomy of X or 21; triploidy; tetraploidy; single, double or triple trisomy; structural alterations, either balanced or unbalanced; combined monosomy/trisomy; all present in larger published studies. […] Ascertainment bias, tissue culture failure and maternal contamination either in the sample or during tissue culture will all affect data sets.

• #10 Recurrent miscarriage – Wikipedia

  https://en.wikipedia.org/wiki/Recurrent_miscarriage

  Recurrent miscarriage or recurrent pregnancy loss (RPL) is the spontaneous loss of 2-3 pregnancies that is estimated to affect up to 5% of women. The exact cause of pregnancy loss is unexplained despite genetic testing and a thorough evaluation. When a cause for RPL is identified, almost half are attributed to a chromosomal abnormality (ie. aneuploidy). RPL has been associated with several risk factors including parental and genetic factors (ie. advanced maternal age, chromosomal abnormalities, sperm DNA fragmentation), congenital and acquired anatomical conditions, lifestyle factors (ie. cigarette smoking, caffeine, alcohol, stress), endocrine disorders, thrombophila (clotting disorders), immunological factors, and infections. The cause of recurrent pregnancy is unknown in about 50% of cases. Risk factors that have been associated with RPL include parental and genetic factors (advanced maternal age, chromosomal abnormalities, sperm DNA fragmentation), anatomical conditions, lifestyle factors, endocrine disorders, thrombophila (bleeding disorders), immunological factors, and infections. Despite thorough evaluation for these risk factors, the exact cause for recurrent pregnancy loss is unknown in about 50% of cases. Recurrent pregnancy loss is most commonly found to be caused by chromosomal abnormalities in the fetus, accounting for approximately 50% of cases. These include structural aberrations (such as chromosomal inversions, insertions, deletions, and translocations) and numerical aberrations, also called aneuploidies (trisomies, monosomy X, and triploidy). An important example is the possible increased risk of miscarriage in women with thrombophilia (propensity for blood clots). The most common problem is the factor V Leiden and prothrombin G20210A mutation. Some preliminary studies suggest that anticoagulant medication may improve the chances of carrying pregnancy to term but these studies need to be confirmed before they are adopted in clinical practice. A common feature of immune factors in causing recurrent pregnancy loss appears to be a decreased maternal immune tolerance towards the fetus. The antiphospholipid syndrome is an autoimmune disease that is a common cause of recurrent pregnancy loss.

• #11 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #12 1st trimester miscarriage: four decades of study – Hardy – Translational Pediatrics

  https://tp.amegroups.org/article/view/6176/7081

  Miscarriage is a very common occurrence in humans. This paper sets out to present published data on research that has provided increased understanding of pregnancy failure. […] Early studies used cytogenetic methods and tissue culture to obtain results. These studies demonstrated the significant contribution of unbalanced chromosomal karyotypes to pregnancy failure. Maternal age as a contributing factor in trisomy was clearly demonstrated. First trimester miscarriage exhibits very high cytogenetic abnormality; in contrast to very low rates in later losses. Cytogenetic methods investigate whole genomes, and are considered to represent the standard against which new methods must be validated. […] Maternal meiotic errors most commonly lead to autosomal trisomy. Use of molecular methods has provided the opportunity to determine parental origin and stage of meiosis in trisomic miscarriages. Maternal meiosis I (MMI) contributed towards 68% of trisomy 13 cases, 64% to 77% in trisomy 21, and 90% in trisomy 16. Maternal error (both first and second meiotic division) was demonstrated for 95% of informative cases in trisomy 18.

• #13 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  It has long been an enigma how the implanting embryo and trophoblast escape maternal immunological rejection in the uterus in spite of carrying allogeneic proteins encoded by paternal genes. A series of mechanisms regulating maternal immune recognition and fetal antigen expression has been suggested to prevent the rejection of the majority of pregnancies, but these may cause RM when they fail. […] There is general agreement that a series of autoantibodies such as anti-phospholipid, anti-nuclear and anti-thyroid antibodies can be found with increased prevalence in RM patients and may display a negative prognostic impact. […] The most convincing evidence for the importance of the immune system in miscarriage and RM comes from genetic/epidemiologic studies showing that genetic biomarkers of possible importance for immunologic dysregulation in pregnancy are found with increased frequency in women with RM and display a negative impact on the prognosis.

• #14 NLRP3 inflammasome as the potential target mechanism and therapy in recurrent spontaneous abortions

  https://www.spandidos-publications.com/10.3892/mmr.2019.9829

  Recurrent spontaneous abortions (RSA) are defined as aborting three or more times within 20 gestational weeks with the same sexual partner. […] The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, which is an important component of innate immunity, serves a role in the immune response and in disease occurrence. […] It was demonstrated that the disordered regulation of the NLRP3 inflammasome may induce the occurrence of RSA. […] The present study demonstrated that the activated NLRP3 inflammasome was involved in the pathogenesis of RSA through regulation of the Th17 and regulatory T cell imbalance. […] The NLRP3 inflammasome is closely associated with autoimmune diseases, which indicates that the NLRP3 inflammasome may be associated with the occurrence of recurrent miscarriage. […] The results demonstrated that the NLRP3 inflammasome was activated in patients with RSA. […] The results demonstrated that the activated NLRP3 inflammasome is involved in the pathogenesis of RSA by regulating the Th17 and Treg balance disturbance.

• #15 Miscarriage: Risk Factors and Prevention | Article | GLOWM

  https://www.glowm.com/article/heading/vol-19–pregnancy-shortening-etiology-prediction-and-prevention–miscarriage-risk-factors-and-prevention/id/419023

  Chromosomal abnormalities are found in 60% of miscarried material but less than 1% of live births when prenatal diagnosis is not used. […] Inappropriate decidualization can result from changes in immune cells, primarily because of uterine natural killer cells, Th1 cytokines high release and as a result activation of pro-inflammatory reaction, especially the thrombosis mechanism in the trophoblast which result in miscarriage. […] Antiphospholipid syndrome, thyroid autoantibodies, and subclinical hypothyroidism are associated with miscarriage and recurrent pregnancy loss (RPL). […] Bicornuate uterus, unicornuate, duplication of reproductive organs, and uterine septae have been associated with spontaneous and recurrent miscarriage. […] Various immunological markers, including elevated concentrations of natural killer cells, dysregulated cytokines, and the presence of antiphospholipid antibodies or other autoantibodies, have been linked to miscarriages. […] The recurrent miscarriage is associated with an increased risk of cardiovascular disease and venous thromboembolism.

• #16 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  It has long been an enigma how the implanting embryo and trophoblast escape maternal immunological rejection in the uterus in spite of carrying allogeneic proteins encoded by paternal genes. A series of mechanisms regulating maternal immune recognition and fetal antigen expression has been suggested to prevent the rejection of the majority of pregnancies, but these may cause RM when they fail. […] There is general agreement that a series of autoantibodies such as anti-phospholipid, anti-nuclear and anti-thyroid antibodies can be found with increased prevalence in RM patients and may display a negative prognostic impact. […] The most convincing evidence for the importance of the immune system in miscarriage and RM comes from genetic/epidemiologic studies showing that genetic biomarkers of possible importance for immunologic dysregulation in pregnancy are found with increased frequency in women with RM and display a negative impact on the prognosis.

• #17 About APS | antiphospholipid syndrome | Pregnancy

  https://aps-support.org.uk/about-aps/what-are-the-symptoms/pregnancy

  APS is usually associated with recurrent miscarriage, but it can also cause other pregnancy complications. […] At least 15% of recurrent miscarriages occur as a result of APS, and it is now recognised as the most common, treatable cause. […] The majority of miscarriages in women with APS occur at the early stages of pregnancy in the first 13 weeks. […] The antiphospholipid antibodies (aPL) cause early miscarriages because they prevent the pregnancy from embedding properly in the womb, and inhibit the growth of the early foetal cells. […] The antibodies act in a different way in later pregnancy loss than with early miscarriage, by causing clots in the small and delicate veins in the placenta. […] It is now thought that pre-eclampsia is caused by a lack of blood being supplied to the placenta. As antiphospholipid antibodies (aPL) can damage the placenta by causing clots in the small vessels, it is highly likely this is why it is so common among women with APS. […] In women with APS, the antiphospholipid antibodies damage the placenta and can prevent the baby growing to normal size, so the baby is small at birth.

• #18 About APS | antiphospholipid syndrome | Pregnancy

  https://aps-support.org.uk/about-aps/what-are-the-symptoms/pregnancy

  APS is usually associated with recurrent miscarriage, but it can also cause other pregnancy complications. […] At least 15% of recurrent miscarriages occur as a result of APS, and it is now recognised as the most common, treatable cause. […] The majority of miscarriages in women with APS occur at the early stages of pregnancy in the first 13 weeks. […] The antiphospholipid antibodies (aPL) cause early miscarriages because they prevent the pregnancy from embedding properly in the womb, and inhibit the growth of the early foetal cells. […] The antibodies act in a different way in later pregnancy loss than with early miscarriage, by causing clots in the small and delicate veins in the placenta. […] It is now thought that pre-eclampsia is caused by a lack of blood being supplied to the placenta. As antiphospholipid antibodies (aPL) can damage the placenta by causing clots in the small vessels, it is highly likely this is why it is so common among women with APS. […] In women with APS, the antiphospholipid antibodies damage the placenta and can prevent the baby growing to normal size, so the baby is small at birth.

• #19 NLRP3 Inflammasome in the Pathogenesis of Miscarriages

  https://www.mdpi.com/1422-0067/25/19/10513

  NLRP3 Inflammasome in the Pathogenesis of Miscarriages […] Despite significant advances in prenatal medicine, spontaneous miscarriage remains one of the most common and serious pregnancy complications, affecting an increasing number of women. […] The aim of this study has been to assess the involvement of the NLRP3 inflammasome as a potential causative factor. […] Significantly higher concentrations of NLRP3 and IL-18 were demonstrated in the serum of patients with miscarriage as compared to the control group. […] In the placental tissue samples, a higher expression of IL-1β, IL-18, and Caspase-1 proteins was noted in women who had experienced miscarriage as compared to the control group. […] The analysis of the results indicated a greater involvement of the inflammasome in women with spontaneous miscarriage associated with oxidative–antioxidative imbalance than in the case of miscarriage related to NET formation. […] Our research has provided evidence for the involvement of the inflammasome in the process of spontaneous miscarriage and identifies a new direction for diagnostics that includes NLRP3 as a preventive element in prenatal care, particularly in light of the steadily declining number of pregnancies and the increasing number of reproductive failures.

• #20 NLRP3 Inflammasome in the Pathogenesis of Miscarriages

  https://www.mdpi.com/1422-0067/25/19/10513

  The observed increase in serum levels of NLRP3 and IL-18 in the patients with spontaneous abortion suggests a potential involvement of the inflammasome in this obstetric failure. […] This hypothesis is supported by the high expression of IL-1β and IL-18, along with elevated levels of Caspase-1 in the placenta tissue of women who experienced miscarriage. […] The activation of the NLRP3 inflammasome and Caspase-1, along with the release of inflammatory cytokines (IL-1β and IL-18), occurs as a result of intense calcium and potassium efflux through the membrane integrity disruption in the cell, leading to mitochondrial damage and the generation of reactive oxygen species (ROS). […] The statistical analysis of our results, considering the two patient groups, revealed that significant changes in IL-1β and IL-18 levels, as well as higher NLRP3 levels, are characteristic of the NET-negative patients. […] The results obtained from the tissues of the NET-positive patients indicate the local activation of the inflammasome, potentially involving other cells.

• #21 Hormones.gr

  http://www.hormones.gr/8509/article/hormonal-causes-of-recurrent-pregnancy-loss%E2%80%A6.html

  Endocrine disorders play a major role in approximately 8% to 12% of recurrent pregnancy loss (RPL). Indeed, the local hormonal milieu is crucial in both embryo attachment and early pregnancy. Endocrine abnormalities, including thyroid disorders, luteal phase defects, polycystic ovary syndrome, hyperprolactinaemia and diabetes have to be evaluated in any case of RPL. […] The pathophysiological mechanisms of RPL are as yet poorly understood and the aetiologies remain unexplained in up to 50% of affected couples. This reproductive disorder is a challenge to the clinician because genetic, endocrinological, anatomic, immunologic, thrombophilic and iatrogenic data may be required for a complete evaluation. […] The purpose of this article is to review the pathophysiology of endocrinological diseases causing RPL.

• #22 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #23 The role of progesterone in miscarriage

  https://www.contemporaryobgyn.net/view/progesterone-in-miscarriage

  Low progesterone levels have been associated with an increased rate of miscarriage. […] In early pregnancy, progesterone is critical for the maintenance of pregnancy. Excising the corpus luteum early in pregnancy (luteectomy) results in decreased progesterone levels. Subsequently miscarriage occurs, unless exogenous progesterone is administered. […] Low progesterone levels have been associated with an increased rate of miscarriage, but whether these low levels are the cause or solely the consequence of a failed pregnancy is unclear. […] A Cochrane review that included 7 randomized controlled trials, with a total of 696 participants, concluded that progesterone probably reduces the risk of miscarriage with a relative risk (RR) of 0.64 and a confidence interval CI of 0.47 to 0.87. […] The most common cause of early pregnancy loss is chromosomal abnormalities. They account for approximately 60% of early miscarriages, with a lower prevalence in women with more advanced gestation and among those with RPL.

• #24 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #25 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #26 Evaluation and treatment of recurrent pregnancy loss: a committee opinion (2012) | American Society for Reproductive Medicine | ASRM

  https://www.asrm.org/practice-guidance/practice-committee-documents/evaluation-and-treatment-of-recurrent-pregnancy-loss-a-committee-opinion-2012/

  Congenital uterine abnormalities are associated with second trimester pregnancy loss in addition to other complications, including preterm labor, fetal malpresentation, and increased rates of cesarean delivery. Although the role of uterine malformations in first-trimester RPL is debatable, assessment of uterine anatomy is widely recommended. A high incidence of pregnancy loss occurred in patients with septate, bicornuate, and arcuate uteri. Correction of septate defects in particular may have beneficial effects and should be considered in women with RPL. […] It is generally agreed that maternal endocrine disorders (e.g., diabetes, thyroid dysfunction) should be evaluated and treated. Well-controlled diabetes is not a risk factor for RPL. However, uncontrolled diabetes is associated with increased pregnancy loss. Prolactin is commonly measured because elevated prolactin levels are associated with ovulatory dysfunction. Hyperprolactinemia may be associated with recurrent pregnancy loss through alterations in the hypothalamic-pituitary-ovarian axis, resulting in impaired folliculogenesis and oocyte maturation, and/or a short luteal phase.

• #27 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #28 The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism | European Journal of Medical Research | Full Text

  https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-023-01161-z

  Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. […] Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidationreduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. […] The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies. […] In recent years, a developing number of studies have demonstrated that metabolism is altered during pregnancy and has a significant impact on pregnancy outcomes.

• #29 The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism | European Journal of Medical Research | Full Text

  https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-023-01161-z

  In conclusion, the abnormal lipid metabolism provoked by the decrease in PPAR and the increases in PUFA and TG can promote inflammation and oxidative stress, which would contribute to miscarriage. […] In conclusion, abnormal amino acid metabolism can act in several pregnancy-related tissues, leading to adverse pregnancy outcomes. […] Research on hyperandrogenemia and insulin resistance-related miscarriage in women showed that the important factors contributing to embryonic damage in polycystic ovary syndrome (PCOS)-like conditions include excessive production of ROS, mitochondrial dysfunction, and the inhibition of superoxide dismutase 1 (SOD1) and Keap1/Nrf2 antioxidant responses in the placenta. […] In conclusion, reduced GLUT protein expression during pregnancy affects glycogen transport synthesis in the endometrium, which leads to insufficient substrates for gluconeogenesis and induces RSA. […] The link between genetics and metabolism might contribute to further insights into the genetic mechanisms leading to spontaneous miscarriages.

• #30 The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism | European Journal of Medical Research | Full Text

  https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-023-01161-z

  In conclusion, the abnormal lipid metabolism provoked by the decrease in PPAR and the increases in PUFA and TG can promote inflammation and oxidative stress, which would contribute to miscarriage. […] In conclusion, abnormal amino acid metabolism can act in several pregnancy-related tissues, leading to adverse pregnancy outcomes. […] Research on hyperandrogenemia and insulin resistance-related miscarriage in women showed that the important factors contributing to embryonic damage in polycystic ovary syndrome (PCOS)-like conditions include excessive production of ROS, mitochondrial dysfunction, and the inhibition of superoxide dismutase 1 (SOD1) and Keap1/Nrf2 antioxidant responses in the placenta. […] In conclusion, reduced GLUT protein expression during pregnancy affects glycogen transport synthesis in the endometrium, which leads to insufficient substrates for gluconeogenesis and induces RSA. […] The link between genetics and metabolism might contribute to further insights into the genetic mechanisms leading to spontaneous miscarriages.

• #31 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Nevertheless, in approximately 50–75% of RPL cases, the exact cause is not clearly identified and, therefore, remains unexplained (idiopathic). […] The contribution of uterine structural anomalies to the etiology of RPL was reported in several studies and found to be present in about 7–28% of women with RPL compared with 4–7% of women in the general population. […] The most common congenital uterine anomalies include septate uteri, arcuate, and bicorporal uteri. […] Among patients with congenital uterine defects, women with a septate uteri have the highest incidence of recurrent miscarriage. […] A lot has been reported on the role of genetic factors in RPL, as chromosomal abnormalities are one of the significant causes of miscarriage in the first trimester of pregnancy. […] Genetic risk factors, including abnormal embryonic genotypes and parental chromosomal rearrangements, could be a background for more than 50% of RPL cases.

• #32 Abortion | PPT

  https://www.slideshare.net/slideshow/abortion-54257120/54257120

  Abortion is defined as the expulsion or extraction of an embryo or fetus weighing 500 g or less from its mother when it is not capable of independent survival (i.e. before the period of viability). […] Etiology can include fetal factors like genetic abnormalities and maternal factors like endocrine/metabolic issues, infections, immunological disorders, and environmental exposures. […] 50% of early miscarriage is due to chromosomal abnormalities. […] In majority, the exact cause is not known. […] Recurrent miscarriage is defined as a sequence of three or more consecutive spontaneous abortion. […] Genetic factors (35%): Parental chromosomal abnormalities. […] The most common cause for 1st trimester loss is a balanced translocation. […] Anatomic abnormalities – responsible for 10-15% of recurrent abortion.

• #33 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Nevertheless, in approximately 50–75% of RPL cases, the exact cause is not clearly identified and, therefore, remains unexplained (idiopathic). […] The contribution of uterine structural anomalies to the etiology of RPL was reported in several studies and found to be present in about 7–28% of women with RPL compared with 4–7% of women in the general population. […] The most common congenital uterine anomalies include septate uteri, arcuate, and bicorporal uteri. […] Among patients with congenital uterine defects, women with a septate uteri have the highest incidence of recurrent miscarriage. […] A lot has been reported on the role of genetic factors in RPL, as chromosomal abnormalities are one of the significant causes of miscarriage in the first trimester of pregnancy. […] Genetic risk factors, including abnormal embryonic genotypes and parental chromosomal rearrangements, could be a background for more than 50% of RPL cases.

• #34 Miscarriage – Wikipedia

  https://en.wikipedia.org/wiki/Miscarriage

  Autoimmunity is a possible cause of recurrent or late-term miscarriages. In the case of an autoimmune-induced miscarriage, the woman’s body attacks the growing fetus or prevents normal pregnancy progression. Autoimmune disease may cause abnormalities in embryos, which in turn may lead to miscarriage. Approximately 15% of recurrent miscarriages are related to immunologic factors. […] Fifteen percent of women who have experienced three or more recurring miscarriages have some anatomical defect that prevents the pregnancy from being carried for the entire term. The structure of the uterus affects the ability to carry a child to term. Anatomical differences are common and can be congenital. […] Ingesting food that has been contaminated with listeriosis, toxoplasmosis, and salmonella is associated with an increased risk of miscarriage.

• #35 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Nevertheless, in approximately 50–75% of RPL cases, the exact cause is not clearly identified and, therefore, remains unexplained (idiopathic). […] The contribution of uterine structural anomalies to the etiology of RPL was reported in several studies and found to be present in about 7–28% of women with RPL compared with 4–7% of women in the general population. […] The most common congenital uterine anomalies include septate uteri, arcuate, and bicorporal uteri. […] Among patients with congenital uterine defects, women with a septate uteri have the highest incidence of recurrent miscarriage. […] A lot has been reported on the role of genetic factors in RPL, as chromosomal abnormalities are one of the significant causes of miscarriage in the first trimester of pregnancy. […] Genetic risk factors, including abnormal embryonic genotypes and parental chromosomal rearrangements, could be a background for more than 50% of RPL cases.

• #36 Abortion | PPT

  https://www.slideshare.net/slideshow/abortion-54257120/54257120

  Cervical Insufficiency (Incompetence) Painless cervical dilatation with ballooning of amniotic sac into vagina, followed by rupture of membrane and expulsion of fetus. […] The procedure reinforces the weak cervix by a non-absorbable tape, placed around the cervix at the level of internal os. […] The overall risk of recurrent miscarriage is about 25-30% irrespective of the number of previous spontaneous miscarriage.

• #37 Evaluation and treatment of recurrent pregnancy loss: a committee opinion (2012) | American Society for Reproductive Medicine | ASRM

  https://www.asrm.org/practice-guidance/practice-committee-documents/evaluation-and-treatment-of-recurrent-pregnancy-loss-a-committee-opinion-2012/

  Congenital uterine abnormalities are associated with second trimester pregnancy loss in addition to other complications, including preterm labor, fetal malpresentation, and increased rates of cesarean delivery. Although the role of uterine malformations in first-trimester RPL is debatable, assessment of uterine anatomy is widely recommended. A high incidence of pregnancy loss occurred in patients with septate, bicornuate, and arcuate uteri. Correction of septate defects in particular may have beneficial effects and should be considered in women with RPL. […] It is generally agreed that maternal endocrine disorders (e.g., diabetes, thyroid dysfunction) should be evaluated and treated. Well-controlled diabetes is not a risk factor for RPL. However, uncontrolled diabetes is associated with increased pregnancy loss. Prolactin is commonly measured because elevated prolactin levels are associated with ovulatory dysfunction. Hyperprolactinemia may be associated with recurrent pregnancy loss through alterations in the hypothalamic-pituitary-ovarian axis, resulting in impaired folliculogenesis and oocyte maturation, and/or a short luteal phase.

• #38 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] An accepted cause of recurrent pregnancy loss is uterine malformations that may be acquired or congenital. […] It is well known that early miscarriage is normally associated with low or suboptimally increasing hCG levels. […] Recently, evidence has been presented suggesting that epigenetic disruptions may lie behind some instances of early pregnancy loss. […] The emerging role of the endometrium as a biosensor of embryo quality, which may be less discerning in some women, also provides a novel mechanism underlying RM that merits further study.

• #39

  https://discovery.ucl.ac.uk/1446281/

  The presented thesis is an investigation of the incidence and pathophysiology of first trimester threatened miscarriage and its outcomes. First trimester threatened miscarriage is the commonest complication of pregnancy, affecting 10-20% of women with clinically recognised pregnancies, and the incidence and mechanisms for long term adverse outcomes are poorly understood. […] Early placental development requires a delicate balance between the entry of oxygenated maternal blood and the capacity of the villous trophoblast to metabolise oxygen and eliminate its metabolites (free radicals). There is a rapid increase in placental markers of oxidative stress as the maternal circulation is established, which may serve a physiological role in stimulating placental differentiation, but which equally may result in free radical damage if antioxidant defences are depleted.

• #40

  https://discovery.ucl.ac.uk/1446281/

  The presented thesis is an investigation of the incidence and pathophysiology of first trimester threatened miscarriage and its outcomes. First trimester threatened miscarriage is the commonest complication of pregnancy, affecting 10-20% of women with clinically recognised pregnancies, and the incidence and mechanisms for long term adverse outcomes are poorly understood. […] Early placental development requires a delicate balance between the entry of oxygenated maternal blood and the capacity of the villous trophoblast to metabolise oxygen and eliminate its metabolites (free radicals). There is a rapid increase in placental markers of oxidative stress as the maternal circulation is established, which may serve a physiological role in stimulating placental differentiation, but which equally may result in free radical damage if antioxidant defences are depleted.

• #41

  https://discovery.ucl.ac.uk/1446281/

  Bleeding in early pregnancy could change the delicate equilibrium of placental production of reactive oxygen species and its natural antioxidant defences, leading to disruption of normal development of the early placenta and placental membranes. This disruption results in a range of adverse pregnancy outcomes, from miscarriage in the first trimester, to pre-term pre-labour rupture of the membranes, pre-term labour, fetal growth restriction and pre eclampsia in the third. […] This study examines in detail the incidence and possible mechanisms of adverse outcome in women with threatened miscarriage and the role of placental function, in terms of placental hormone production and markers of oxidative stress, in both the causation of threatened miscarriage and the subsequent outcome of the pregnancy. It confirms an association between threatened miscarriage and adverse outcome, and provides potential markers of placental damage or stress to add to a growing body of research elucidating the role of oxidative stress in the developing placenta and later pregnancy complications.

• #42 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality. […] The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] This novel concept requires further elucidation and confirmation, but a growing body of evidence supports the notion of an active, selective decidual phenotype, which if disrupted may result in reproductive failure.

• #43 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Sporadic miscarriages are considered to primarily represent failure of abnormal embryos to progress to viability. […] In recent years, new theories about the mechanisms behind sporadic and recurrent miscarriage have emerged. […] Recent experimental evidence has led to the concept that the decidualized endometrium acts as a biosensor of embryo quality, which if disrupted, may lead to implantation of embryos destined to miscarry. […] It is a generally accepted assumption that sporadic pregnancy losses occurring before an embryo has developed represent a physiological phenomenon, which prevents conceptions affected by serious structural malformations or chromosomal aberrations incompatible with life from progressing to viability. […] The hypothesis that endometrial selectivity to embryo quality may be disrupted in women with RM has found support from a number of other studies.

• #44 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality. […] The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] This novel concept requires further elucidation and confirmation, but a growing body of evidence supports the notion of an active, selective decidual phenotype, which if disrupted may result in reproductive failure.

• #45 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  Proposed treatment options for RM where immunologic dysregulation is suggested to play a role include prednisone, allogeneic lymphocyte immunization, intravenous immunoglobulin infusion and injection of tumor necrosis factor (TNF) antagonists or granulocyte colony-stimulating factor (G-CSF). […] Thrombophilic factors predisposing to thromboembolic events are associated with both sporadic miscarriages and RM and can be hereditary or acquired. […] The prevalence of hypothyroidism with or without underlying thyroid autoimmunity is significant among fertile women in fertile age. […] The mechanisms behind an increased miscarriage risk in women with PCOS remains partly unclear. […] In contrast, there is a documented link between DNA damage in sperm and miscarriage. […] Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality.

• #46 Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

  https://www.mdpi.com/2077-0383/12/12/4074

  Endocrine disorders play a significant role in approximately 12–20% of RPL. […] The role of infection in first-trimester RPL remains unclear. […] Thrombophilia and the predisposition to improper coagulation can affect chorionic blood flow and cause vasculopathy leading to pregnancy loss. […] The immune response control is important for a successful pregnancy and related to the link between genetic variants and increased risk of RPL. […] Vitamin D deficiency is a growing global health concern. […] Many lines of evidence implicate defective vitamin D activity with a heightened risk of RPL. […] Other risk factors for RPL include stress, alcohol, smoking, ethnicity, a history of previous miscarriage and preterm birth, and environmental factors. […] The strong association between cigarette smoking and poor pregnancy outcomes was reported.

• #47 Recurrent miscarriage – Wikipedia

  https://en.wikipedia.org/wiki/Recurrent_miscarriage

  Recurrent miscarriage or recurrent pregnancy loss (RPL) is the spontaneous loss of 2-3 pregnancies that is estimated to affect up to 5% of women. The exact cause of pregnancy loss is unexplained despite genetic testing and a thorough evaluation. When a cause for RPL is identified, almost half are attributed to a chromosomal abnormality (ie. aneuploidy). RPL has been associated with several risk factors including parental and genetic factors (ie. advanced maternal age, chromosomal abnormalities, sperm DNA fragmentation), congenital and acquired anatomical conditions, lifestyle factors (ie. cigarette smoking, caffeine, alcohol, stress), endocrine disorders, thrombophila (clotting disorders), immunological factors, and infections. The cause of recurrent pregnancy is unknown in about 50% of cases. Risk factors that have been associated with RPL include parental and genetic factors (advanced maternal age, chromosomal abnormalities, sperm DNA fragmentation), anatomical conditions, lifestyle factors, endocrine disorders, thrombophila (bleeding disorders), immunological factors, and infections. Despite thorough evaluation for these risk factors, the exact cause for recurrent pregnancy loss is unknown in about 50% of cases. Recurrent pregnancy loss is most commonly found to be caused by chromosomal abnormalities in the fetus, accounting for approximately 50% of cases. These include structural aberrations (such as chromosomal inversions, insertions, deletions, and translocations) and numerical aberrations, also called aneuploidies (trisomies, monosomy X, and triploidy). An important example is the possible increased risk of miscarriage in women with thrombophilia (propensity for blood clots). The most common problem is the factor V Leiden and prothrombin G20210A mutation. Some preliminary studies suggest that anticoagulant medication may improve the chances of carrying pregnancy to term but these studies need to be confirmed before they are adopted in clinical practice. A common feature of immune factors in causing recurrent pregnancy loss appears to be a decreased maternal immune tolerance towards the fetus. The antiphospholipid syndrome is an autoimmune disease that is a common cause of recurrent pregnancy loss.

• #48 Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

  https://www.degruyter.com/document/doi/10.1515/mr-2022-0030/html?lang=en

  Studies have shown that embryonic chromosome anomalies can also explain RPL. […] However, compared with sporadic spontaneous pregnancy loss, women with RPL have a decreased embryonic chromosomal aneuploidy rate. […] A series of studies suggest that thrombophilia might increase womens risk for RPL by impairing normal placental vascular function. […] It is important to note that thrombosis or occlusion of placental vessels may decrease placental perfusion, which may contribute to adverse pregnancy outcomes including RPL. […] A large number of genetic predisposing factors to RPL have been identified currently. […] As aforementioned, the RPL-associated genes are enriched in various functional categories, such as chromosomal abnormalities, thrombosis and immune responses. […] Future work, focusing on the combined effects of environmental risk factors and genetic variants, is expected to yield more results to delineate the etiology of RPL.

• #49 Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

  https://www.degruyterbrill.com/document/doi/10.1515/mr-2022-0030/html?lang=en&srsltid=AfmBOoqf3rBONMtfGJdLaMf6_LVwZF1bVLXlf0b72miJ4EpmAHvCliKM

  Studies have shown that PTS, either hereditary or acquired, is associated with an increased risk of RPL. […] Recent single-cell transcriptomics analyses show that reduction of specific dNK subsets such as CD27CD11b, pregnancy trained dNK, and CSF1+ CD59+ KIRs may be related to RPL. […] The disturbance of these processes caused by dNK cells dysfunction may be related to RPL. […] A series of studies suggest that thrombophilia might increase women’s risk for RPL by impairing normal placental vascular function. […] The fetus expresses the antigens of paternal origin, and just like a semi-allograft, the fetus is foreign to the maternal immune system. Therefore, fetomaternal immune tolerance is essential for the maintenance of a healthy pregnancy. […] Studies have demonstrated that multiple interleukin (IL) genes are associated with RPL susceptibility.

• #50 Miscarriage | Pathology, Symptoms & Treatment | Britannica

  https://www.britannica.com/science/miscarriage

  miscarriage, spontaneous expulsion of the embryo or fetus from the uterus before the 20th week of pregnancy, prior to the conceptus having developed sufficiently to live without maternal support. An estimated 10 to 25 percent of recognized pregnancies are lost as a result of miscarriage, with the risk of loss being highest in the first six weeks of pregnancy. […] The most common cause, accounting for more than 60 percent of miscarriages, is an inherited defect in the fetus, which might result in a deformed or otherwise abnormal child. An acute infectious disease may play a role in causing some miscarriages, particularly if it reduces the oxygen supply to the fetus. Certain uterine tumours or other uterine abnormalities also may induce a miscarriage. Death of the fetus stemming from external trauma or from knotting of the umbilical cord is another cause of miscarriage.

• #51 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #52 Miscarriage – Women’s Health Issues – MSD Manual Consumer Version

  https://www.msdmanuals.com/home/women-s-health-issues/early-pregnancy-disorders/miscarriage

  Most of the time, the cause of a miscarriage is unknown, but it may occur because the fetus is not developing normally (sometimes because of a genetic abnormality or birth defect) or because of a health issue in the pregnant woman such as a structural abnormality of the reproductive organs, infection, use of substances (for example, cocaine, alcohol, or cigarette smoking), or an injury. […] Miscarriages that occur during the first 10 to 11 weeks of pregnancy are often caused by a chromosome disorder. This occurs more frequently in women who are younger than 20 years old or are 35 or older. […] Anatomic abnormalities in the woman’s reproductive tract (for example, a uterus that has fibroids or, rarely, 2 chambers or internal scarring) may also cause pregnancy loss through 20 weeks of pregnancy. A miscarriage may result from certain viral infections, such as a cytomegalovirus infection or rubella. Other causes include medical conditions, such as diabetes or autoimmune disorders.

• #53 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #54 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #55 Miscarriage – Wikipedia

  https://en.wikipedia.org/wiki/Miscarriage

  Autoimmunity is a possible cause of recurrent or late-term miscarriages. In the case of an autoimmune-induced miscarriage, the woman’s body attacks the growing fetus or prevents normal pregnancy progression. Autoimmune disease may cause abnormalities in embryos, which in turn may lead to miscarriage. Approximately 15% of recurrent miscarriages are related to immunologic factors. […] Fifteen percent of women who have experienced three or more recurring miscarriages have some anatomical defect that prevents the pregnancy from being carried for the entire term. The structure of the uterus affects the ability to carry a child to term. Anatomical differences are common and can be congenital. […] Ingesting food that has been contaminated with listeriosis, toxoplasmosis, and salmonella is associated with an increased risk of miscarriage.

• #56 Causes of Miscarriage: List of Possible Causes | Ada

  https://ada.com/causes-of-miscarriage/

  If the placenta does not form or function correctly throughout pregnancy, this is likely to negatively affect the development of the fetus, causing a miscarriage. […] Particular medications are unsuitable for pregnant women and using them can cause miscarriage or (teratogenic) abnormalities and/or malformations. […] The exact mechanisms by which diseases and infections cause miscarriage is not yet fully understood. […] Not all cases of disease or infection lead to miscarriage, but it is important to seek medical attention promptly if an infection is suspected, as effective treatment can significantly reduce the likelihood of this outcome. […] Many of the long-term health conditions which are associated with miscarriage are immune disorders, conditions which can prevent the fetus and placenta from being properly protected from the body’s regular immune response.

• #57 The male contribution to recurrent pregnancy loss – Ibrahim – Translational Andrology and Urology

  https://tau.amegroups.org/article/view/19793/html

  There are several known causes of recurrent pregnancy loss (RPL) in a couple, which include endocrine abnormalities, immunologic abnormalities, structural uterine abnormalities and karyotype abnormalities. […] The male contribution to RPL remains understudied. […] Chromosomal abnormalities are well defined causes of pregnancy losses in the literature. However, despite the fact that abnormal DNA fragmentation has been implicated in the pathogenesis of unexplained RPL, it is not routinely checked during the evaluation of RPL. […] This is likely due to the fact that abnormal DNA fragmentation is the end result of multiple different mechanisms including environmental exposures, varicoceles, gene alteration and epigenetic changes resulting in an inherent susceptibility to DNA damage. […] We are just beginning to scratch the surface of our understanding of the male contribution to RPL and more studies especially focusing on epigenetic modifications and gene alterations are needed.

• #58 The male contribution to recurrent pregnancy loss – Ibrahim – Translational Andrology and Urology

  https://tau.amegroups.org/article/view/19793/html

  Higher sperm DNA fragmentation in couples with RPL may have its origin in poor DNA packaging at chromatin remodeling during spermiogenesis, which could leave DNA more vulnerable to oxidative stress and DNA nucleases. […] Several studies have suggested an association between increased sperm DNA fragmentation and unexplained RPL. […] Although ASRM does not recommend routine sperm DNA fragmentation testing in male partners of women with unexplained RPL, current evidence since that guideline was published suggests that this could provide a potential mechanism for a male contribution to unexplained RPL. […] Furthermore, we are just beginning to explore the possibility that some men could have an unrecognized inherent genetic predisposition that causes their spermatozoa DNA to become susceptible to fragmentation.

• #59 The male contribution to recurrent pregnancy loss – Ibrahim – Translational Andrology and Urology

  https://tau.amegroups.org/article/view/19793/html

  Despite some of the evidence for DNA fragmentation as a potential etiology of RPL, there are some limitations for its use. […] The presence of severe oligospermia or azoospermia on routine semen analysis warrants further investigation including evaluation for microdeletion of the azoospermic factor (AZF) on the Y chromosome. […] Several investigators have studied the prevalence of Y-chromosome microdeletions in their populations of couples with RPL. […] We are now beginning to understand that genetic and epigenetic contributions of sperm to early embryogenesis are extensive and have profound clinical implications. […] Sperm aneuploidy has been detected at an increased rate in male partners of women with RPL compared to controls in several studies. […] The 2015 ASRM practice guideline for evaluation of the infertile male suggests that patients with RPL may benefit from screening for sperm aneuploidy.

• #60 The male contribution to recurrent pregnancy loss – Ibrahim – Translational Andrology and Urology

  https://tau.amegroups.org/article/view/19793/html

  Despite some of the evidence for DNA fragmentation as a potential etiology of RPL, there are some limitations for its use. […] The presence of severe oligospermia or azoospermia on routine semen analysis warrants further investigation including evaluation for microdeletion of the azoospermic factor (AZF) on the Y chromosome. […] Several investigators have studied the prevalence of Y-chromosome microdeletions in their populations of couples with RPL. […] We are now beginning to understand that genetic and epigenetic contributions of sperm to early embryogenesis are extensive and have profound clinical implications. […] Sperm aneuploidy has been detected at an increased rate in male partners of women with RPL compared to controls in several studies. […] The 2015 ASRM practice guideline for evaluation of the infertile male suggests that patients with RPL may benefit from screening for sperm aneuploidy.

• #61 The male contribution to recurrent pregnancy loss – Ibrahim – Translational Andrology and Urology

  https://tau.amegroups.org/article/view/19793/html

  Recent studies have reported an association between differentially methylated areas in the sperm DNA and male fecundity. […] Unexplained RPL as a result of early embryogenesis defect is one degree of separation away from male fecundity and it remains to be explored, the role of differential DNA methylation profiles in male partners of women with unexplained RPL. […] RPL is a multifactorial disease and we are just beginning to scratch the surface of understanding the male contribution to unexplained RPL.

• #62 The threshold effect of factors associated with spontaneous abortion in human-assisted reproductive technology | Scientific Reports

  https://www.nature.com/articles/s41598-021-90970-5

  In addition, the older the male age, the higher the incidence of abortion. […] However, technological progress does not prevent and avoid spontaneous abortion (SAB), and a study showed that the incidence of early pregnancy loss in ART patients receiving fresh embryo transplantation is 14.9%. […] Considering the burden of spontaneous abortion on families and society, it is necessary to explore and determine the prevalence and risk factors linked to miscarriage in infertile couples, especially for infertile couples assisted by ART. […] Our study retrospectively analyzed the clinical data of 16,097 patients who received ART treatment and successfully conceived at the Shangqiu First People’s Hospital from June 2013 to December 2018. […] The individual parameters and laboratory data of both husbands and wives were included to explore the associated factors of spontaneous abortion.

• #63 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #64 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #65 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #66 Impaired serum thiol/disulphide homeostasis may be another explanation for the pathogenesis of missed abortion

  https://www.imrpress.com/journal/CEOG/46/1/10.12891/ceog4316.2019

  Impaired serum thiol/disulphide homeostasis may be another explanation for the pathogenesis of missed abortion […] Oxidative stress is an important factor in pregnancy physiology and embryogenesis. Placental oxidative stress results from deficient trophoblast invasion found to be a cause of a spectrum of disorders including miscarriage, missed miscarriage, and early- and late-onset preeclampsia. […] The authors found a significant increase in serum disulphide levels from the oxidative stress markers in patients with missed abortion.

• #67 Impaired serum thiol/disulphide homeostasis may be another explanation for the pathogenesis of missed abortion

  https://www.imrpress.com/journal/CEOG/46/1/10.12891/ceog4316.2019

  Impaired serum thiol/disulphide homeostasis may be another explanation for the pathogenesis of missed abortion […] Oxidative stress is an important factor in pregnancy physiology and embryogenesis. Placental oxidative stress results from deficient trophoblast invasion found to be a cause of a spectrum of disorders including miscarriage, missed miscarriage, and early- and late-onset preeclampsia. […] The authors found a significant increase in serum disulphide levels from the oxidative stress markers in patients with missed abortion.

• #68

  http://reproduct-endo.com/article/view/237613

  Study objective: to determine the dynamics of type 9 metalloproteinase (MMP-9) and its tissue inhibitor-1 (TIMP-1) in the pathogenesis of early miscarriage in women with chronic diseases of the hepatobiliary system. […] MMP-9 and TIMP-1 growth in the blood serum of women with a history of miscarriage was established in the pre-gravidar period. The most significant increase in the parameters of the intercellular matrix was found in patients with non-alcoholic steatohepatitis. […] There is an imbalance between MMP-9 and TIMP-1 in the blood serum in women with early miscarriage and chronic diseases of the hepatobiliary system. […] MMP-9 increased during physiological pregnancy, and the TIMP-1 activity practically did not change, which indicates the role of MMP-9 in the initial stages of placentation. […] Such changes in MMP-9 and TIMP-1 in patients with miscarriage indicate the accumulation of intercellular matrix and sclerotic changes in the vessels that provide blood to the uterus.

• #69

  http://reproduct-endo.com/article/view/237613

  Study objective: to determine the dynamics of type 9 metalloproteinase (MMP-9) and its tissue inhibitor-1 (TIMP-1) in the pathogenesis of early miscarriage in women with chronic diseases of the hepatobiliary system. […] MMP-9 and TIMP-1 growth in the blood serum of women with a history of miscarriage was established in the pre-gravidar period. The most significant increase in the parameters of the intercellular matrix was found in patients with non-alcoholic steatohepatitis. […] There is an imbalance between MMP-9 and TIMP-1 in the blood serum in women with early miscarriage and chronic diseases of the hepatobiliary system. […] MMP-9 increased during physiological pregnancy, and the TIMP-1 activity practically did not change, which indicates the role of MMP-9 in the initial stages of placentation. […] Such changes in MMP-9 and TIMP-1 in patients with miscarriage indicate the accumulation of intercellular matrix and sclerotic changes in the vessels that provide blood to the uterus.

• #70

  http://reproduct-endo.com/article/view/237613

  Study objective: to determine the dynamics of type 9 metalloproteinase (MMP-9) and its tissue inhibitor-1 (TIMP-1) in the pathogenesis of early miscarriage in women with chronic diseases of the hepatobiliary system. […] MMP-9 and TIMP-1 growth in the blood serum of women with a history of miscarriage was established in the pre-gravidar period. The most significant increase in the parameters of the intercellular matrix was found in patients with non-alcoholic steatohepatitis. […] There is an imbalance between MMP-9 and TIMP-1 in the blood serum in women with early miscarriage and chronic diseases of the hepatobiliary system. […] MMP-9 increased during physiological pregnancy, and the TIMP-1 activity practically did not change, which indicates the role of MMP-9 in the initial stages of placentation. […] Such changes in MMP-9 and TIMP-1 in patients with miscarriage indicate the accumulation of intercellular matrix and sclerotic changes in the vessels that provide blood to the uterus.

• #71 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  Proposed treatment options for RM where immunologic dysregulation is suggested to play a role include prednisone, allogeneic lymphocyte immunization, intravenous immunoglobulin infusion and injection of tumor necrosis factor (TNF) antagonists or granulocyte colony-stimulating factor (G-CSF). […] Thrombophilic factors predisposing to thromboembolic events are associated with both sporadic miscarriages and RM and can be hereditary or acquired. […] The prevalence of hypothyroidism with or without underlying thyroid autoimmunity is significant among fertile women in fertile age. […] The mechanisms behind an increased miscarriage risk in women with PCOS remains partly unclear. […] In contrast, there is a documented link between DNA damage in sperm and miscarriage. […] Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality.

• #72 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality. […] The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] This novel concept requires further elucidation and confirmation, but a growing body of evidence supports the notion of an active, selective decidual phenotype, which if disrupted may result in reproductive failure.

• #73 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  Proposed treatment options for RM where immunologic dysregulation is suggested to play a role include prednisone, allogeneic lymphocyte immunization, intravenous immunoglobulin infusion and injection of tumor necrosis factor (TNF) antagonists or granulocyte colony-stimulating factor (G-CSF). […] Thrombophilic factors predisposing to thromboembolic events are associated with both sporadic miscarriages and RM and can be hereditary or acquired. […] The prevalence of hypothyroidism with or without underlying thyroid autoimmunity is significant among fertile women in fertile age. […] The mechanisms behind an increased miscarriage risk in women with PCOS remains partly unclear. […] In contrast, there is a documented link between DNA damage in sperm and miscarriage. […] Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality.

• #74 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Sporadic miscarriages are considered to primarily represent failure of abnormal embryos to progress to viability. […] In recent years, new theories about the mechanisms behind sporadic and recurrent miscarriage have emerged. […] Recent experimental evidence has led to the concept that the decidualized endometrium acts as a biosensor of embryo quality, which if disrupted, may lead to implantation of embryos destined to miscarry. […] It is a generally accepted assumption that sporadic pregnancy losses occurring before an embryo has developed represent a physiological phenomenon, which prevents conceptions affected by serious structural malformations or chromosomal aberrations incompatible with life from progressing to viability. […] The hypothesis that endometrial selectivity to embryo quality may be disrupted in women with RM has found support from a number of other studies.

• #75 New insights into mechanisms behind miscarriage

  https://pmc.ncbi.nlm.nih.gov/articles/PMC3699442/

  Recent in vitro studies of embryo-decidual interactions have demonstrated that decidualized stromal cells act as a biosensor for embryonic derived signals and appear capable of selecting embryos for implantation on the basis of their quality. […] The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] This novel concept requires further elucidation and confirmation, but a growing body of evidence supports the notion of an active, selective decidual phenotype, which if disrupted may result in reproductive failure.

• #76 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  A spontaneous abortion is a process that can be divided into 4 stages: threatened, inevitable, incomplete, and complete. The combination of oxidative stress, a more hypoxic environment, and defective placentation may lead to increased serum ischemia-modified albumin (IMA) concentrations, which in turn, may play a role in the pathophysiology of early pregnancy loss. […] In the first trimester, embryonic causes of spontaneous abortion are the predominant etiology and account for 80-90% of miscarriages. […] One study suggested that an inflammatory reaction occurs in normal pregnancy and may be disrupted during miscarriage. […] Genetic abnormalities within the embryo (ie, chromosomal abnormalities) are the most common cause of spontaneous abortion and account for 50-65% of all miscarriages. The most common single chromosomal anomaly is 45,X karyotype, with an incidence of 14.6%. Trisomies are the single largest group of chromosomal anomalies and account for approximately one half of all anomalies associated with miscarriage.

• #77 NLRP3 inflammasome as the potential target mechanism and therapy in recurrent spontaneous abortions

  https://www.spandidos-publications.com/10.3892/mmr.2019.9829

  Recurrent spontaneous abortions (RSA) are defined as aborting three or more times within 20 gestational weeks with the same sexual partner. […] The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, which is an important component of innate immunity, serves a role in the immune response and in disease occurrence. […] It was demonstrated that the disordered regulation of the NLRP3 inflammasome may induce the occurrence of RSA. […] The present study demonstrated that the activated NLRP3 inflammasome was involved in the pathogenesis of RSA through regulation of the Th17 and regulatory T cell imbalance. […] The NLRP3 inflammasome is closely associated with autoimmune diseases, which indicates that the NLRP3 inflammasome may be associated with the occurrence of recurrent miscarriage. […] The results demonstrated that the NLRP3 inflammasome was activated in patients with RSA. […] The results demonstrated that the activated NLRP3 inflammasome is involved in the pathogenesis of RSA by regulating the Th17 and Treg balance disturbance.

• #78 NLRP3 inflammasome as the potential target mechanism and therapy in recurrent spontaneous abortions

  https://www.spandidos-publications.com/10.3892/mmr.2019.9829

  Recurrent spontaneous abortions (RSA) are defined as aborting three or more times within 20 gestational weeks with the same sexual partner. […] The NACHT, LRR and PYD domains-containing protein 3 (NLRP3) inflammasome, which is an important component of innate immunity, serves a role in the immune response and in disease occurrence. […] It was demonstrated that the disordered regulation of the NLRP3 inflammasome may induce the occurrence of RSA. […] The present study demonstrated that the activated NLRP3 inflammasome was involved in the pathogenesis of RSA through regulation of the Th17 and regulatory T cell imbalance. […] The NLRP3 inflammasome is closely associated with autoimmune diseases, which indicates that the NLRP3 inflammasome may be associated with the occurrence of recurrent miscarriage. […] The results demonstrated that the NLRP3 inflammasome was activated in patients with RSA. […] The results demonstrated that the activated NLRP3 inflammasome is involved in the pathogenesis of RSA by regulating the Th17 and Treg balance disturbance.

• #79 Blighted Ovum (Anembryonic Pregnancy): Causes & Symptoms

  https://my.clevelandclinic.org/health/diseases/21924-blighted-ovum

  A blighted ovum (also called an anembryonic pregnancy) is a type of early miscarriage that occurs when a fertilized egg implants into your uterus but doesn’t develop into an embryo. The fertilized egg stops growing, but the gestational sac (where the embryo would develop) continues to grow. The placenta and empty gestational sac will release pregnancy hormones, even without an embryo present. This causes you to have early symptoms of pregnancy or even have a positive pregnancy test. Sometimes, it occurs so early in pregnancy that you don’t know you’re pregnant. […] A blighted ovum causes an early miscarriage in the first trimester of pregnancy. During fetal development, a fertilized egg turns into a blastocyte. At around four weeks of pregnancy, this blastocyte implants in the wall of your uterus and develops into an embryo. When you have a blighted ovum, the gestational sac that would hold the embryo continues to grow, even without an embryo present.

• #80 Blighted Ovum (Anembryonic Pregnancy): Causes & Symptoms

  https://my.clevelandclinic.org/health/diseases/21924-blighted-ovum

  A blighted ovum is the No. 1 cause of first-trimester miscarriages. […] A blighted ovum is usually the result of chromosomal problems that occur during cell division. This can happen because the egg or sperm is poor quality or due to an error that occurs at random. […] With a blighted ovum, the embryo never forms or stops growing after it forms. This may be because your body recognizes there is a chromosomal problem and naturally stops the pregnancy from continuing to grow. […] Your chances of having another blighted ovum are low. If you experience more than one blighted ovum, your healthcare provider may suggest genetic testing to determine if there’s an underlying cause.

• #81 Causes of Miscarriage: List of Possible Causes | Ada

  https://ada.com/causes-of-miscarriage/

  Immunological abnormalities which may cause miscarriage can stem from the pregnant person being affected by factors including: […] If a person who wishes to become pregnant knows that they are affected by any condition associated with an improper immune response to pregnancy, they should seek medical attention before trying to conceive. […] Compared with the causes discussed above, miscarriage may be caused fairly rarely by additional factors including: […] A miscarriage may be caused by one or more changeable or unchangeable factors. […] It may be possible to find out the causes of a miscarriage by performing an autopsy on the pregnancy tissue and/or a placental exam (an analysis of the placenta).

• #82 Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study | The BMJ

  https://www.bmj.com/content/364/bmj.l869

  Objectives To estimate the burden of miscarriage in the Norwegian population and to evaluate the associations with maternal age and pregnancy history. […] The risk of miscarriage varies greatly with maternal age, shows a strong pattern of recurrence, and is also increased after some adverse pregnancy outcomes. Miscarriage and other pregnancy complications might share underlying causes, which could be biological conditions or unmeasured common risk factors. […] Although the cause of most miscarriages is unknown, they presumably result from a complex interplay between parental age, genetic, hormonal, immunological, and environmental factors. […] Maternal age is the strongest known risk factor. The risk of miscarriage is slightly elevated in the youngest mothers and then rises sharply in older mothers.

• #83 Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study | The BMJ

  https://www.bmj.com/content/364/bmj.l869

  Objectives To estimate the burden of miscarriage in the Norwegian population and to evaluate the associations with maternal age and pregnancy history. […] The risk of miscarriage varies greatly with maternal age, shows a strong pattern of recurrence, and is also increased after some adverse pregnancy outcomes. Miscarriage and other pregnancy complications might share underlying causes, which could be biological conditions or unmeasured common risk factors. […] Although the cause of most miscarriages is unknown, they presumably result from a complex interplay between parental age, genetic, hormonal, immunological, and environmental factors. […] Maternal age is the strongest known risk factor. The risk of miscarriage is slightly elevated in the youngest mothers and then rises sharply in older mothers.

• #84 Early Pregnancy Loss | ACOG

  https://www.acog.org/womens-health/faqs/early-pregnancy-loss

  About half of early miscarriages happen when the embryo does not develop properly. This often is due to an abnormal number of chromosomes. Chromosomes are in each cell of the body and carry the blueprints (genes) for how people develop and function. […] If an egg or sperm has more or fewer chromosomes than normal, the embryo also will have an abnormal number. This can lead to miscarriage. […] The chance of early pregnancy loss increases as a woman gets older. For women over age 40, about 1 in 3 pregnancies end in miscarriage. Most end because of a chromosome abnormality. […] There also is some evidence that chromosome abnormalities in the embryo increase as men get older. But it is not clear at what age this begins for men.

• #85 Early Pregnancy Loss | ACOG

  https://www.acog.org/womens-health/faqs/early-pregnancy-loss

  About half of early miscarriages happen when the embryo does not develop properly. This often is due to an abnormal number of chromosomes. Chromosomes are in each cell of the body and carry the blueprints (genes) for how people develop and function. […] If an egg or sperm has more or fewer chromosomes than normal, the embryo also will have an abnormal number. This can lead to miscarriage. […] The chance of early pregnancy loss increases as a woman gets older. For women over age 40, about 1 in 3 pregnancies end in miscarriage. Most end because of a chromosome abnormality. […] There also is some evidence that chromosome abnormalities in the embryo increase as men get older. But it is not clear at what age this begins for men.

• #86 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #87 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #88 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #89 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Symptoms of vaginal bleeding but not abdominal pain are associated with increased risk of miscarriage. One paper suggests that miscarriage can occur in about 50% of patients who present with threatened abortion. […] A study by Hahn et al indicates that obesity increases the likelihood of spontaneous abortion, with the risk being highest in the first two months of pregnancy. […] Select vaginal bacteria may also increase the risk of early pregnancy loss. […] A Danish nationwide study found that 147 of 3315 women exposed to oral fluconazole in their 7th through 22nd weeks of gestation experienced a spontaneous abortion compared to 563 of the 13,246 unexposed pregnancies.

• #90 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Maternal causes of spontaneous miscarriage include the following: Genetic: Maternal age is directly related to the aneuploidy risk (30% in people aged 40 y). […] Acute maternal factors include the following: Corpus luteum deficiency, Active infection (eg, rubella virus, cytomegalovirus, Listeria infection, toxoplasmosis, malaria, brucellosis, human immunodeficiency virus (HIV), dengue fever, influenza, as well as vaginal infection with bacterial vaginosis). […] Chronic maternal health factors include the following: Polycystic ovary syndrome, Poorly controlled diabetes mellitus, Renal disease, Systemic lupus erythematosus (SLE), Untreated thyroid disease. […] Independent risk factors for a spontaneous miscarriage include advanced age, extremes of age, feeling stressed, and advanced paternal age.

• #91 Early Pregnancy Loss (Spontaneous Abortion) – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK560521/

  In more than 60% of pregnancy losses between 6 to 10 weeks of gestation, the etiology is believed to be fetal chromosomal abnormalities, including trisomies, monosomy, and polyploidy. Additionally, inflammatory and immunologic dysregulation is thought to play a role in some cases, likely due to the effect on trophoblastic invasion. […] The most common risk factor for early pregnancy loss is advanced maternal age. For example, the incidence of early pregnancy loss in women aged 20 to 30 years is only 9% to 17%, while the incidence at 45 years of maternal age is 75% to 80%. […] Several chronic diseases can predispose a pregnant patient to early pregnancy loss, including obesity, diabetes, hyperprolactinemia, celiac disease, thyroid disease, and autoimmune conditions, particularly antiphospholipid syndrome. Furthermore, some infections are associated with an increased risk of early pregnancy loss, such as syphilis, parvovirus B19, Zika virus, and cytomegalovirus infections.

• #92 Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study | The BMJ

  https://www.bmj.com/content/364/bmj.l869

  The risk of miscarriage was increased if the previous pregnancy ended in a preterm delivery, caesarean section, or if the woman had gestational diabetes. […] The risk of miscarriage was moderately increased among women who had experienced a stillbirth, preterm delivery, or gestational diabetes in their previous pregnancy. […] The risk of miscarriage was slightly higher in women who themselves had been small for gestational age. […] The associations of risk of miscarriage with complications in previous pregnancies point to the presence of causal factors that increase the risk of both.

• #93 Miscarriage | Pathology, Symptoms & Treatment | Britannica

  https://www.britannica.com/science/miscarriage

  Endocrine disorders such as deficient secretion of the hormone progesterone may cause poor development of the decidua (the mucal lining of the uterus) or an abnormally irritable uterus and may thus sometimes result in miscarriage. […] Women over age 35 tend to be at increased risk of miscarriage relative to younger women. Risk factors include the presence of a preexisting medical condition such as thyroid disease, a history of miscarriage, and prenatal testing such as amniocentesis. Smoking, drinking alcohol, or taking certain drugs during pregnancy are also recognized risk factors.

• #94 Miscarriage | Pathology, Symptoms & Treatment | Britannica

  https://www.britannica.com/science/miscarriage

  Endocrine disorders such as deficient secretion of the hormone progesterone may cause poor development of the decidua (the mucal lining of the uterus) or an abnormally irritable uterus and may thus sometimes result in miscarriage. […] Women over age 35 tend to be at increased risk of miscarriage relative to younger women. Risk factors include the presence of a preexisting medical condition such as thyroid disease, a history of miscarriage, and prenatal testing such as amniocentesis. Smoking, drinking alcohol, or taking certain drugs during pregnancy are also recognized risk factors.

• #95 Miscarriage: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/001488.htm

  A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. […] Most miscarriages are caused by chromosome problems that make it impossible for the fetus to develop. […] Other possible causes of miscarriage may include: Drug or alcohol use, Blood clotting disorders, Exposure to environmental toxins, Hormone problems, Infection, Obesity, Physical problems with the mother’s reproductive organs, Problem with the body’s immune response, Serious body-wide (systemic) diseases in the mother (such as uncontrolled diabetes), Smoking. […] Around half of all fertilized eggs die and are lost (aborted) spontaneously, usually before the woman knows she is pregnant. […] The risk for miscarriage is higher: In women who are older — The risk increases after 30 years of age and becomes even greater between 35 and 40 years, and is highest after age 40. […] Miscarriages that are caused by systemic diseases can be prevented by detecting and treating the disease before pregnancy occurs. […] Taking a prenatal vitamin or folic acid supplement before you become pregnant can greatly lower the chances of miscarriage and certain birth defects.

• #96 Miscarriage: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/001488.htm

  A miscarriage is the spontaneous loss of a fetus before the 20th week of pregnancy. […] Most miscarriages are caused by chromosome problems that make it impossible for the fetus to develop. […] Other possible causes of miscarriage may include: Drug or alcohol use, Blood clotting disorders, Exposure to environmental toxins, Hormone problems, Infection, Obesity, Physical problems with the mother’s reproductive organs, Problem with the body’s immune response, Serious body-wide (systemic) diseases in the mother (such as uncontrolled diabetes), Smoking. […] Around half of all fertilized eggs die and are lost (aborted) spontaneously, usually before the woman knows she is pregnant. […] The risk for miscarriage is higher: In women who are older — The risk increases after 30 years of age and becomes even greater between 35 and 40 years, and is highest after age 40. […] Miscarriages that are caused by systemic diseases can be prevented by detecting and treating the disease before pregnancy occurs. […] Taking a prenatal vitamin or folic acid supplement before you become pregnant can greatly lower the chances of miscarriage and certain birth defects.

• #97 Causes of Miscarriage: List of Possible Causes | Ada

  https://ada.com/causes-of-miscarriage/

  A miscarriage is a fairly common complication of early pregnancy, in which the developing embryo or fetus dies in the womb of natural causes, or due to exposure to substances, i.e. in certain medications, which are unsuitable for use during pregnancy. […] Most miscarriages are early miscarriages, and are caused by factors including: […] Chromosomal (DNA) abnormalities, which are present in the fetus. […] Problems with the placenta, the organ responsible for the exchange of nutrients and gases between the pregnant person and the fetus. […] Certain long-term health conditions, particularly immunological disorders, such as diabetes or systemic lupus erythematosus, may cause early or late miscarriage. […] The leading causes of late miscarriage include: […] Environmental factors, such as exposure to radiation.

• #98 Miscarriage: Causes, Symptoms, Risks, Treatment & Prevention

  https://my.clevelandclinic.org/health/diseases/9688-miscarriage

  A miscarriage is the loss of a pregnancy before 20 weeks gestation. Most miscarriages happen in the first trimester of pregnancy. Chromosomal problems cause most miscarriages. […] Chromosomal abnormalities cause about 50% of all miscarriages in the first trimester (up to 13 weeks) of pregnancy. […] Most chromosomal problems occur by chance. Its not completely known why this happens. […] Several factors may cause miscarriage: Infection, Exposure to TORCH diseases, Hormonal imbalances, Improper implantation of fertilized egg in your uterine lining, How old you are, Uterine abnormalities, Incompetent cervix (your cervix begins to open too early in pregnancy), Lifestyle factors such as smoking, drinking alcohol or using recreational drugs, Disorders of the immune system like lupus, Severe kidney disease, Congenital heart disease, Diabetes that isn’t managed, Thyroid disease, Radiation, Certain medicines, such as the acne drug isotretinoin (Accutane), Severe malnutrition. […] There is no scientific proof that stress, exercise, sexual activity or prolonged use of birth control pills cause miscarriage.

• #99 Pregnancy week by week

  https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/early-miscarriage/faq-20058214

  Miscarriage is the loss of a pregnancy before the 20th week. It also may be called a spontaneous abortion. It’s estimated that about 10% to 20% of known pregnancies end in miscarriage. But the actual number is likely higher. That’s because many miscarriages happen very early in pregnancy, before people realize they’re pregnant. […] Most often, early miscarriage is caused by a problem in the chromosomes that disrupts an embryo’s development. But research has found that some forms of stress may raise the risk of a miscarriage. […] Stress that lasts, called chronic stress, or high levels of sudden stress, called acute stress, may raise the risk of miscarriage. […] That kind of stress can have a negative effect on the body and on a person’s health overall. For example, chronic stress can cause the level of the hormone cortisol to rise. That can lead to changes in the immune system. It can cause problems in the way the body processes sugar. Intense or ongoing stress also has the potential to make the body more vulnerable to infections. All of these factors may raise the risk of pregnancy loss. […] But managing any ongoing health conditions, such as diabetes or thyroid disease; staying at a healthy weight; and avoiding behaviors such as smoking, drinking alcohol and using drugs, can keep you healthier and may lower your risk of miscarriage.

• #100 Pregnancy week by week

  https://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/expert-answers/early-miscarriage/faq-20058214

  Miscarriage is the loss of a pregnancy before the 20th week. It also may be called a spontaneous abortion. It’s estimated that about 10% to 20% of known pregnancies end in miscarriage. But the actual number is likely higher. That’s because many miscarriages happen very early in pregnancy, before people realize they’re pregnant. […] Most often, early miscarriage is caused by a problem in the chromosomes that disrupts an embryo’s development. But research has found that some forms of stress may raise the risk of a miscarriage. […] Stress that lasts, called chronic stress, or high levels of sudden stress, called acute stress, may raise the risk of miscarriage. […] That kind of stress can have a negative effect on the body and on a person’s health overall. For example, chronic stress can cause the level of the hormone cortisol to rise. That can lead to changes in the immune system. It can cause problems in the way the body processes sugar. Intense or ongoing stress also has the potential to make the body more vulnerable to infections. All of these factors may raise the risk of pregnancy loss. […] But managing any ongoing health conditions, such as diabetes or thyroid disease; staying at a healthy weight; and avoiding behaviors such as smoking, drinking alcohol and using drugs, can keep you healthier and may lower your risk of miscarriage.

• #101 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Symptoms of vaginal bleeding but not abdominal pain are associated with increased risk of miscarriage. One paper suggests that miscarriage can occur in about 50% of patients who present with threatened abortion. […] A study by Hahn et al indicates that obesity increases the likelihood of spontaneous abortion, with the risk being highest in the first two months of pregnancy. […] Select vaginal bacteria may also increase the risk of early pregnancy loss. […] A Danish nationwide study found that 147 of 3315 women exposed to oral fluconazole in their 7th through 22nd weeks of gestation experienced a spontaneous abortion compared to 563 of the 13,246 unexposed pregnancies.

• #102 Miscarriage: Causes, Symptoms, Risks, Treatment & Prevention

  https://my.clevelandclinic.org/health/diseases/9688-miscarriage

  A miscarriage is the loss of a pregnancy before 20 weeks gestation. Most miscarriages happen in the first trimester of pregnancy. Chromosomal problems cause most miscarriages. […] Chromosomal abnormalities cause about 50% of all miscarriages in the first trimester (up to 13 weeks) of pregnancy. […] Most chromosomal problems occur by chance. Its not completely known why this happens. […] Several factors may cause miscarriage: Infection, Exposure to TORCH diseases, Hormonal imbalances, Improper implantation of fertilized egg in your uterine lining, How old you are, Uterine abnormalities, Incompetent cervix (your cervix begins to open too early in pregnancy), Lifestyle factors such as smoking, drinking alcohol or using recreational drugs, Disorders of the immune system like lupus, Severe kidney disease, Congenital heart disease, Diabetes that isn’t managed, Thyroid disease, Radiation, Certain medicines, such as the acne drug isotretinoin (Accutane), Severe malnutrition. […] There is no scientific proof that stress, exercise, sexual activity or prolonged use of birth control pills cause miscarriage.

• #103 Miscarriage – threatened: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/000907.htm

  A threatened miscarriage is a condition that indicates the potential for a miscarriage or early pregnancy loss. It might take place before the 20th week of pregnancy. […] Miscarriage is common. Small falls, injuries or stress during the first trimester of pregnancy can cause threatened miscarriage. It occurs in almost one half of all pregnancies. The chance of miscarriage is higher in older women. About one half of women who have bleeding in the first trimester will have a miscarriage. […] Most women with a threatened miscarriage go on to have a normal pregnancy. […] Women who have had two or more miscarriages in a row may be more likely than other women to miscarry again. […] Most miscarriages cannot be prevented. The most common cause of a miscarriage is a random genetic abnormality in the developing pregnancy. If you have two or more repeated miscarriages, you should consult a specialist to look for an underlying condition that is causing the problem. […] Other factors that can increase your risk for miscarriage include: Obesity, Thyroid problems, Uncontrolled diabetes.

• #104 Abortion | PPT

  https://www.slideshare.net/slideshow/abortion-54257120/54257120

  Cervical Insufficiency (Incompetence) Painless cervical dilatation with ballooning of amniotic sac into vagina, followed by rupture of membrane and expulsion of fetus. […] The procedure reinforces the weak cervix by a non-absorbable tape, placed around the cervix at the level of internal os. […] The overall risk of recurrent miscarriage is about 25-30% irrespective of the number of previous spontaneous miscarriage.

• #105 Miscarriage – Prenatal Genetics – GBMC HealthCare in Baltimore, MD

  https://www.gbmc.org/services/prenatal-genetics/miscarriage-prenatal-genetics

  Miscarriage is the loss of a pregnancy before 20 weeks gestation. There are many reasons for pregnancy loss. In many cases, no cause for past miscarriage(s) is identified. Most causes of miscarriage are not under our control. Approximately 50% of first trimester miscarriages are due to a chromosome abnormality in the fetus. An extra chromosome or a missing chromosome can cause miscarriage, usually in the first or second trimester of pregnancy, or can lead to a child with learning difficulties or intellectual disability and birth defects. Inherited variation with the chromosomes can also cause miscarriage. Extra and missing genetic material lead to „chromosomal imbalance” and can cause intellectual disability and birth defects in a liveborn or cause a miscarriage. Another genetic cause of miscarriage is a change (variant) in one or more genes on the chromosomes. Other reasons for pregnancy loss are related to maternal health. An abnormally shaped uterus can lead to pregnancy loss. Health problems such as hormonal imbalance, poorly-controlled diabetes, lupus and other immune system abnormalities, kidney and heart disease, and hypertension can create difficulties in carrying a pregnancy to term. Another cause of pregnancy loss is an environmental exposure during pregnancy. For example, exposure to certain medications, drugs, alcohol, or high levels of radiation can lead to miscarriage. […] Remember, even when repeated miscarriages occur, there is a good chance of success in a subsequent pregnancy.

• #106 Miscarriage – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/pregnancy-loss-miscarriage/symptoms-causes/syc-20354298

  Sometimes, pregnancy tissue that stays in the uterus after a miscarriage can lead to a uterine infection about 1 to 2 days later. The infection is called a septic miscarriage. […] Heavy bleeding from the vagina, called a hemorrhage, is another miscarriage complication. […] Often, there’s nothing you can do to prevent a miscarriage. Instead, focus on taking good care of yourself and your unborn baby.

• #107 Miscarriage – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/pregnancy-loss-miscarriage/symptoms-causes/syc-20354298

  Sometimes, pregnancy tissue that stays in the uterus after a miscarriage can lead to a uterine infection about 1 to 2 days later. The infection is called a septic miscarriage. […] Heavy bleeding from the vagina, called a hemorrhage, is another miscarriage complication. […] Often, there’s nothing you can do to prevent a miscarriage. Instead, focus on taking good care of yourself and your unborn baby.

• #108 Spontaneous Abortion – Gynecology and Obstetrics – MSD Manual Professional Edition

  https://www.msdmanuals.com/professional/gynecology-and-obstetrics/early-pregnancy-disorders/spontaneous-abortion

  Early spontaneous abortion is often caused by a chromosomal abnormality. Maternal reproductive tract abnormalities (eg, bicornuate uterus, fibroids, adhesions) may also cause pregnancy loss through 20 weeks gestation. Isolated spontaneous abortions may result from certain viral infections most notably cytomegalovirus, herpesvirus, parvovirus, and rubella virus. Other causes include immunologic abnormalities and major physical trauma. Most often, the cause is unknown. […] Spontaneous abortion is often caused by chromosomal abnormalities or maternal reproductive tract abnormalities (eg, bicornuate uterus, fibroids), but etiology in an individual case is usually not confirmed. […] Confirm spontaneous abortion and determine pregnancy status with quantitative beta-hCG, ultrasonography, and pelvic examination; a dilated cervix means that abortion is inevitable.

• #109 Miscarriage: Risk Factors and Prevention | Article | GLOWM

  https://www.glowm.com/article/heading/vol-19–pregnancy-shortening-etiology-prediction-and-prevention–miscarriage-risk-factors-and-prevention/id/419023

  Chromosomal abnormalities are found in 60% of miscarried material but less than 1% of live births when prenatal diagnosis is not used. […] Inappropriate decidualization can result from changes in immune cells, primarily because of uterine natural killer cells, Th1 cytokines high release and as a result activation of pro-inflammatory reaction, especially the thrombosis mechanism in the trophoblast which result in miscarriage. […] Antiphospholipid syndrome, thyroid autoantibodies, and subclinical hypothyroidism are associated with miscarriage and recurrent pregnancy loss (RPL). […] Bicornuate uterus, unicornuate, duplication of reproductive organs, and uterine septae have been associated with spontaneous and recurrent miscarriage. […] Various immunological markers, including elevated concentrations of natural killer cells, dysregulated cytokines, and the presence of antiphospholipid antibodies or other autoantibodies, have been linked to miscarriages. […] The recurrent miscarriage is associated with an increased risk of cardiovascular disease and venous thromboembolism.

• #110 Pathology of Early Pregnancy Loss | SpringerLink

  https://link.springer.com/chapter/10.1007/978-3-030-84168-3_7

  Comprehensive genetic analysis of pregnancy loss by chromosomal microarrays: outcomes, benefits, and challenges. […] Genetics of pregnancy loss. […] Evidence for high frequency of chromosomal mosaicism in spontaneous abortions revealed by interphase FISH analysis. […] The syndromes of hydatidiform mole. II. Morphologic evolution of the complete and partial mole.

• #111 Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

  https://www.degruyter.com/document/doi/10.1515/mr-2022-0030/html?lang=en

  Recurrent pregnancy loss (RPL) has become an important reproductive health issue worldwide. […] However, the etiology of approximately 50% of RPL cases remains unknown (unexplained RPL), which poses a big challenge for clinical management of these patients. RPL has been widely regarded as a complex disease where its etiology has been attributed to numerous factors. […] More importantly, development and applications of next generation sequencing technology have significantly expanded opportunities to discover chromosomal aberrations and single gene variants responsible for RPL, which provides new insight into its pathogenic mechanisms. […] RPL needs more medical intervention and appropriate pregnancy monitoring during future pregnancies. Nowadays, it is widely accepted that RPL belongs to a multifactorial disease, and its causation has been attributed to various factors including chromosome aneuploidy, anatomical uterine defects, immunological dysfunction, endocrinological abnormalities, genetic variants as well as lifestyle influences.

• #112 Genetic analysis of chorionic villus tissues in early missed abortions | Scientific Reports

  https://www.nature.com/articles/s41598-023-48358-0

  Chromosomal abnormalities are the most common etiology of early spontaneous miscarriage. […] The objective of our study was to investigate the efficiency of molecular karyotyping technology for genetic diagnosis of early missed abortion tissues. […] Our study suggests that both SNP array and CNV-seq/QF-PCR are reliable, robust, and high-resolution technologies for genetic diagnosis of miscarriage. […] Embryonic chromosomal numerical abnormalities accounted for up to 90% of the causes of early miscarriage. […] It is well known that segmental deletion and/or duplication can cause miscarriage. […] However, specific data regarding the association between submicroscopic CNVs and spontaneous miscarriage is still limited. […] The overall rate of clinically significant chromosomal abnormalities was 59.7% (693/1160), which is similar to the reported rates in previous researches.

• #113 Causes of Early Miscarriages at 6-8 Weeks

  https://centerforhumanreprod.com/reproductive-health-blog/causes-of-early-miscarriages-at-6-8-weeks

  Correct differentiation between chromosomal and immunologic causes of miscarriages is, of course, of great clinical importance: Unless passed down from a parent, true chromosomal abnormalities in a pregnancy are random events and, therefore (unless a patient experiences repeat miscarriages) not predictive of future miscarriage risk. Immunological miscarriages, however, do denote automatic repeat miscarriage risk.

• #114 Progestogen for preventing miscarriage | Cochrane

  https://www.cochrane.org/CD003511/PREG_progestogen-preventing-miscarriage

  For women with unexplained recurrent miscarriages, supplementation with progestogen therapy may reduce the rate of miscarriage in subsequent pregnancies. […] It has been suggested that a causative factor in many cases of miscarriage may be inadequate secretion of progesterone. Therefore, clinicians use progestogens (drugs that interact with the progesterone receptors), beginning in the first trimester of pregnancy, in an attempt to prevent spontaneous miscarriage. […] The meta-analysis of all women suggests that there may be a reduction in the number of miscarriages for women given progestogen supplementation compared to placebo/controls (average risk ratio (RR) 0.73, 95% confidence interval (CI) 0.54 to 1.00, 10 trials, 1684 women, moderate-quality evidence).

• #115 Recurrent Pregnancy Loss – Medical Clinical Policy Bulletins | Aetna

  https://www.aetna.com/cpb/medical/data/300_399/0348.html

  Inflammatory cytokine cascades have been implicated in the pathogenesis of recurrent pregnancy loss (RPL). […] Polymorphisms in cytokine genes may affect the risk of recurrent pregnancy loss, but genetic association studies are often limited by small sample sizes. […] A systematic evidence review found insufficient evidence for plasminogen activator inhibitor 4G/5G polymorphism testing in recurrent miscarriage. […] The RCOG recommends that in women with recurrent miscarriage who have undergone the above investigations should undergo the following management: That all future treatment options are evaluated in randomized controlled trials; That treatments of unproven benefit should be abandoned; That women with persistently positive tests for anti-phospholipid antibodies are offered treatment with low dose aspirin together with low dose heparin during pregnancy; Those with karyotypic abnormalities should be seen by a clinical geneticist.

• #116 Evaluation and treatment of recurrent pregnancy loss: a committee opinion (2012) | American Society for Reproductive Medicine | ASRM

  https://www.asrm.org/practice-guidance/practice-committee-documents/evaluation-and-treatment-of-recurrent-pregnancy-loss-a-committee-opinion-2012/

  Congenital uterine abnormalities are associated with second trimester pregnancy loss in addition to other complications, including preterm labor, fetal malpresentation, and increased rates of cesarean delivery. Although the role of uterine malformations in first-trimester RPL is debatable, assessment of uterine anatomy is widely recommended. A high incidence of pregnancy loss occurred in patients with septate, bicornuate, and arcuate uteri. Correction of septate defects in particular may have beneficial effects and should be considered in women with RPL. […] It is generally agreed that maternal endocrine disorders (e.g., diabetes, thyroid dysfunction) should be evaluated and treated. Well-controlled diabetes is not a risk factor for RPL. However, uncontrolled diabetes is associated with increased pregnancy loss. Prolactin is commonly measured because elevated prolactin levels are associated with ovulatory dysfunction. Hyperprolactinemia may be associated with recurrent pregnancy loss through alterations in the hypothalamic-pituitary-ovarian axis, resulting in impaired folliculogenesis and oocyte maturation, and/or a short luteal phase.

• #117

  https://journals.lww.com/co-obgyn/fulltext/2005/12000/recurrent_miscarriage__pathophysiology_and_outcome.8.aspx

  This article reviews new concepts in the aetiology of recurrent miscarriage, presents new outcome data and evaluates new modalities of treatment for unexplained recurrent miscarriage. […] Preimplantation genetic diagnosis has been considered an option for couples who have structural chromosomal abnormalities or unexplained recurrent miscarriage. The association between thrombophilias and adverse pregnancy outcome is further reviewed. In relation to this, there is increasing support for the use of thromboprophylaxis in improving pregnancy outcome in women with inherited thrombophilias. […] Nonrandomized studies have shown that the reduction in insulin levels with metformin in insulin-resistant individuals may reduce miscarriage risk by restoring normal haemostasis and improving the endometrial milieu.

• #118

  https://link.springer.com/article/10.1007/s00404-003-0560-3

  Most women with alloimmune cause of recurrent spontaneous abortion (RSA) includes increased sharing of human leukocyte antigens (HLA) that may prohibit the mother from making anti-paternal cyto-toxic antibodies (APCA), anti-idiotypic antibodies (Ab2) and mixed lymphocyte reaction blocking antibodies (MLR-Bf). […] Overactivity of T helper-1 (Th-1) cytokines and natural killer (NK) cells have been also reported to be the major alloimmune cause of recurrent spontaneous abortion (RSA). […] It was revealed from extensive updated analysis of this subject that paternal lymphocytes immunotherapy may play a significant role in the prevention of alloimmune cause of fetal loss in women with RSA. […] These alloimmune parameters are found to be suppressed in successful immunotherapy, which is comparable to normal pregnancy.

• #119 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Recurrent-miscarriage-treatment.aspx

  Due to the uncertainty of diagnosis in such a high percentage of cases of recurrent miscarriage, also known as recurrent pregnancy loss (RPL), the management of RPL is still undergoing evolution. […] While some causes have been identified, such as chromosomal abnormalities, endocrine diseases, hereditary and acquired thrombophilias, and uterine anatomical anomalies, no obvious reason for abortion is identified in about half of all cases. […] Immunologic research is going on to explore the role of natural killer and T-regulatory cells, as well as many cytokines and antigenic proteins, in the etiology of recurrent miscarriage. […] Despite much study, the etiology of RPL is far from clear in half of all cases, and therefore management of unexplained RPL is also evolving with research. Known causes should be effectively controlled, such as APS, autoimmune rheumatologic and endocrinologic disorders. Karyotyping is useful in selected cases.

• #120 Miscarriage – threatened: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/000907.htm

  A threatened miscarriage is a condition that indicates the potential for a miscarriage or early pregnancy loss. It might take place before the 20th week of pregnancy. […] Miscarriage is common. Small falls, injuries or stress during the first trimester of pregnancy can cause threatened miscarriage. It occurs in almost one half of all pregnancies. The chance of miscarriage is higher in older women. About one half of women who have bleeding in the first trimester will have a miscarriage. […] Most women with a threatened miscarriage go on to have a normal pregnancy. […] Women who have had two or more miscarriages in a row may be more likely than other women to miscarry again. […] Most miscarriages cannot be prevented. The most common cause of a miscarriage is a random genetic abnormality in the developing pregnancy. If you have two or more repeated miscarriages, you should consult a specialist to look for an underlying condition that is causing the problem. […] Other factors that can increase your risk for miscarriage include: Obesity, Thyroid problems, Uncontrolled diabetes.

• #121 New insights into mechanisms behind miscarriage | BMC Medicine | Full Text

  https://bmcmedicine.biomedcentral.com/articles/10.1186/1741-7015-11-154

  The clinical significance of these findings remains to be clarified, but failure of embryo selection may represent a single pathological pathway responsible for both euploidic and aneuploidic pregnancy losses. […] An accepted cause of recurrent pregnancy loss is uterine malformations that may be acquired or congenital. […] It is well known that early miscarriage is normally associated with low or suboptimally increasing hCG levels. […] Recently, evidence has been presented suggesting that epigenetic disruptions may lie behind some instances of early pregnancy loss. […] The emerging role of the endometrium as a biosensor of embryo quality, which may be less discerning in some women, also provides a novel mechanism underlying RM that merits further study.

• #122 Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

  https://www.degruyter.com/document/doi/10.1515/mr-2022-0030/html?lang=en

  Importantly, it is worth mentioning that RPL patients caused by OAPS needs more attention and non-standard aPLs tests are worth using in patients negative for classical aPLs but with significant clinical symptoms. […] The disturbance of these processes caused by dNK cells dysfunction may be related to RPL. […] Pregnancy begins with successful implantation of an embryo, and a successful pregnancy requires a combination of factors, in general, including a healthy embryo with a great growth potential and an excellent intrauterine environment with appropriate hormone levels. […] More importantly, several single-cell transcriptomics analyses of decidua have been recently performed, which offer more detailed information on the regulation of immune responses at the maternal-fetal interface.

• #123 Early Pregnancy Loss: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/266317-overview

  Symptoms of vaginal bleeding but not abdominal pain are associated with increased risk of miscarriage. One paper suggests that miscarriage can occur in about 50% of patients who present with threatened abortion. […] A study by Hahn et al indicates that obesity increases the likelihood of spontaneous abortion, with the risk being highest in the first two months of pregnancy. […] Select vaginal bacteria may also increase the risk of early pregnancy loss. […] A Danish nationwide study found that 147 of 3315 women exposed to oral fluconazole in their 7th through 22nd weeks of gestation experienced a spontaneous abortion compared to 563 of the 13,246 unexposed pregnancies.

• #124 NLRP3 Inflammasome in the Pathogenesis of Miscarriages

  https://www.mdpi.com/1422-0067/25/19/10513

  NLRP3 Inflammasome in the Pathogenesis of Miscarriages […] Despite significant advances in prenatal medicine, spontaneous miscarriage remains one of the most common and serious pregnancy complications, affecting an increasing number of women. […] The aim of this study has been to assess the involvement of the NLRP3 inflammasome as a potential causative factor. […] Significantly higher concentrations of NLRP3 and IL-18 were demonstrated in the serum of patients with miscarriage as compared to the control group. […] In the placental tissue samples, a higher expression of IL-1β, IL-18, and Caspase-1 proteins was noted in women who had experienced miscarriage as compared to the control group. […] The analysis of the results indicated a greater involvement of the inflammasome in women with spontaneous miscarriage associated with oxidative–antioxidative imbalance than in the case of miscarriage related to NET formation. […] Our research has provided evidence for the involvement of the inflammasome in the process of spontaneous miscarriage and identifies a new direction for diagnostics that includes NLRP3 as a preventive element in prenatal care, particularly in light of the steadily declining number of pregnancies and the increasing number of reproductive failures.

• #125 CBLL1 behind mechanism in recurrent spontaneous abortion | BioWorld

  https://www.bioworld.com/articles/711499-cbll1-behind-mechanism-in-recurrent-spontaneous-abortion

  CBLL1 behind mechanism in recurrent spontaneous abortion […] Recurrent spontaneous abortion (RSA), also known as recurrent miscarriage, is a disorder related to pregnancy defined as two or more pregnancy losses during the first trimester. It affects about 2%-5% of couples trying to conceive. Chinese researchers have investigated the potential involvement of Cbl proto-oncogene like 1 (CBLL1) in RSA, since CBLL1 has been reported to vary with the menstrual cycle in the endometrium.

• #126 The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism | European Journal of Medical Research | Full Text

  https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-023-01161-z

  Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. […] Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidationreduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. […] The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies. […] In recent years, a developing number of studies have demonstrated that metabolism is altered during pregnancy and has a significant impact on pregnancy outcomes.

Zobacz więcej