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Lancet (London, England) May 2021Miscarriage is generally defined as the loss of a pregnancy before viability. An estimated 23 million miscarriages occur every year worldwide, translating to 44... (Review)
Review
Miscarriage is generally defined as the loss of a pregnancy before viability. An estimated 23 million miscarriages occur every year worldwide, translating to 44 pregnancy losses each minute. The pooled risk of miscarriage is 15·3% (95% CI 12·5-18·7%) of all recognised pregnancies. The population prevalence of women who have had one miscarriage is 10·8% (10·3-11·4%), two miscarriages is 1·9% (1·8-2·1%), and three or more miscarriages is 0·7% (0·5-0·8%). Risk factors for miscarriage include very young or older female age (younger than 20 years and older than 35 years), older male age (older than 40 years), very low or very high body-mass index, Black ethnicity, previous miscarriages, smoking, alcohol, stress, working night shifts, air pollution, and exposure to pesticides. The consequences of miscarriage are both physical, such as bleeding or infection, and psychological. Psychological consequences include increases in the risk of anxiety, depression, post-traumatic stress disorder, and suicide. Miscarriage, and especially recurrent miscarriage, is also a sentinel risk marker for obstetric complications, including preterm birth, fetal growth restriction, placental abruption, and stillbirth in future pregnancies, and a predictor of longer-term health problems, such as cardiovascular disease and venous thromboembolism. The costs of miscarriage affect individuals, health-care systems, and society. The short-term national economic cost of miscarriage is estimated to be £471 million per year in the UK. As recurrent miscarriage is a sentinel marker for various obstetric risks in future pregnancies, women should receive care in preconception and obstetric clinics specialising in patients at high risk. As psychological morbidity is common after pregnancy loss, effective screening instruments and treatment options for mental health consequences of miscarriage need to be available. We recommend that miscarriage data are gathered and reported to facilitate comparison of rates among countries, to accelerate research, and to improve patient care and policy development.
Topics: Abortion, Habitual; Abortion, Spontaneous; Anxiety; Depression; Endometritis; Female; Fetal Growth Retardation; Humans; Premature Birth; Prevalence; Risk Factors; Stillbirth; Stress Disorders, Post-Traumatic; Suicide; Uterine Hemorrhage
PubMed: 33915094
DOI: 10.1016/S0140-6736(21)00682-6 -
Nature Reviews. Disease Primers Dec 2020Recurrent pregnancy loss is a distressing pregnancy disorder experienced by ~2.5% of women trying to conceive. Recurrent pregnancy loss is defined as the failure of two... (Review)
Review
Recurrent pregnancy loss is a distressing pregnancy disorder experienced by ~2.5% of women trying to conceive. Recurrent pregnancy loss is defined as the failure of two or more clinically recognized pregnancies before 20-24 weeks of gestation and includes embryonic and fetal losses. The diagnosis of an early pregnancy loss is relatively straightforward, although progress in predicting and preventing recurrent pregnancy loss has been hampered by a lack of standardized definitions, the uncertainties surrounding the pathogenesis and the highly variable clinical presentation. The prognosis for couples with recurrent pregnancy loss is generally good, although the likelihood of a successful pregnancy depends on maternal age and the number of previous losses. Recurrent pregnancy loss can be caused by chromosomal errors, anatomical uterine defects, autoimmune disorders and endometrial dysfunction. Available treatments target the putative risk factors of pregnancy loss, although the effectiveness of many medical interventions is controversial. Regardless of the underlying aetiology, couples require accurate information on their chances of having a baby and appropriate support should be offered to reduce the psychological burden associated with multiple miscarriages. Future research must investigate the pathogenesis of recurrent pregnancy loss and evaluate novel diagnostic tests and treatments in adequately powered clinical trials.
Topics: Abortion, Spontaneous; Adolescent; Adult; Antiphospholipid Syndrome; Female; Humans; Hypothyroidism; Middle Aged; Pregnancy; Recurrence; Risk Factors; Uterus; Vitamin D Deficiency
PubMed: 33303732
DOI: 10.1038/s41572-020-00228-z -
Australian Family Physician May 2016Twenty to forty per cent of pregnant women will experience bleeding during the first trimester. Initial presentation is usually to the general practitioner.... (Review)
Review
BACKGROUND
Twenty to forty per cent of pregnant women will experience bleeding during the first trimester. Initial presentation is usually to the general practitioner. Complications of miscarriage, including threatened miscarriage and ectopic pregnancy, are the most common diagnoses. The failure to diagnose an ectopic pregnancy may have life-threatening consequences for a woman.
OBJECTIVE
The aim of this article is to review the history, examination findings, investigations and management options for miscarriage and ectopic pregnancy.
DISCUSSION
Early pregnancy bleeding is a very distressing symptom for which a woman seeks reassurance that she has an ongoing pregnancy. It is not always possible to make a diagnosis at the first presentation. In some cases, the need for follow-up investigations or referral to a gynaecologist is required. As healthcare providers, we should continue to review and update our knowledge in the management of this common presentation in order to optimise our care of these patients.
Topics: Abortion, Spontaneous; Female; Humans; Pregnancy; Pregnancy Complications; Pregnancy Trimester, First; Pregnancy, Ectopic; Ultrasonography, Prenatal; Uterine Hemorrhage
PubMed: 27166462
DOI: No ID Found -
Best Practice & Research. Clinical... Nov 2020Progesterone is essential for the maintenance of pregnancy, and progesterone deficiency is associated with miscarriage. The subject of whether progesterone... (Review)
Review
Progesterone is essential for the maintenance of pregnancy, and progesterone deficiency is associated with miscarriage. The subject of whether progesterone supplementation in early pregnancy can prevent miscarriage has been a long-standing research question and has been investigated and debated in the medical literature for over 70 years. During this time, several different progestogens have been synthesised and tested for the prevention of miscarriage. In this chapter, we describe the prior evidence alongside the latest research using micronized natural progesterone as well as synthetic progestogens, which were used to treat both recurrent and threatened miscarriage. The totality of evidence indicates that women with a past history of miscarriage who present with bleeding in early pregnancy may benefit from the use of vaginal micronized progesterone. The clinical implications of the findings are discussed.
Topics: Abortion, Habitual; Abortion, Spontaneous; Abortion, Threatened; Female; Humans; Pregnancy; Progesterone; Progestins; Vagina
PubMed: 32978069
DOI: 10.1016/j.bpobgyn.2020.09.002 -
Human Reproduction Update 2016Miscarriage is the spontaneous loss of a pregnancy before 12 weeks (early miscarriage) or from 12 to 24 weeks (late miscarriage) of gestation. Miscarriage occurs in one... (Review)
Review
BACKGROUND
Miscarriage is the spontaneous loss of a pregnancy before 12 weeks (early miscarriage) or from 12 to 24 weeks (late miscarriage) of gestation. Miscarriage occurs in one in five pregnancies and can have considerable physiological and psychological implications for the patient. It is also associated with significant health care costs. There is evidence that potentially preventable infections may account for up to 15% of early miscarriages and up to 66% of late miscarriages. However, the provision of associated screening and management algorithms is inconsistent for newly pregnant women. Here, we review recent population-based studies on infections that have been shown to be associated with miscarriage.
METHODS
Our aim was to examine where the current scientific focus lies with regards to the role of infection in miscarriage. Papers dating from June 2009 with key words 'miscarriage' and 'infection' or 'infections' were identified in PubMed (292 and 327 papers, respectively, on 2 June 2014). Relevant human studies (meta-analyses, case-control studies, cohort studies or case series) were included. Single case reports were excluded. The studies were scored based on the Newcastle - Ottawa Quality Assessment Scale.
RESULTS
The association of systemic infections with malaria, brucellosis, cytomegalovirus and human immunodeficiency virus, dengue fever, influenza virus and of vaginal infection with bacterial vaginosis, with increased risk of miscarriage has been demonstrated. Q fever, adeno-associated virus, Bocavirus, Hepatitis C and Mycoplasma genitalium infections do not appear to affect pregnancy outcome. The effects of Chlamydia trachomatis, Toxoplasma gondii, human papillomavirus, herpes simplex virus, parvovirus B19, Hepatitis B and polyomavirus BK infections remain controversial, as some studies indicate increased miscarriage risk and others show no increased risk. The latest data on rubella and syphilis indicate increased antenatal screening worldwide and a decrease in the frequency of their reported associations with pregnancy failure. Though various pathogens have been associated with miscarriage, the mechanism(s) of infection-induced miscarriage are not yet fully elucidated.
CONCLUSIONS
Further research is required to clarify whether certain infections do increase miscarriage risk and whether screening of newly pregnant women for treatable infections would improve reproductive outcomes.
Topics: Abortion, Spontaneous; Bacterial Infections; Case-Control Studies; Cohort Studies; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Pregnancy Outcome; Prenatal Diagnosis; Protozoan Infections; Virus Diseases
PubMed: 26386469
DOI: 10.1093/humupd/dmv041 -
Alcoholism, Clinical and Experimental... Aug 2019To systematically review and critically evaluate studies reporting alcohol exposure during pregnancy and miscarriage. We searched PubMed, EMBASE, PsycINFO, and ProQuest... (Meta-Analysis)
Meta-Analysis
To systematically review and critically evaluate studies reporting alcohol exposure during pregnancy and miscarriage. We searched PubMed, EMBASE, PsycINFO, and ProQuest Theses for publications from January 1970 to January 2019. We identified studies about alcohol exposure during pregnancy and miscarriage. Information about study population, alcohol exposure assessment, outcome definition, covariates, and measures of association was collected. We assessed study quality using an adapted Newcastle-Ottawa Scale. Data were abstracted by 2 investigators independently. We conducted a random-effects meta-analysis to calculate the association between alcohol exposure and miscarriage risk and performed subgroup analyses to determine robustness of results to study differences. For studies reporting dose-specific effects, a pooled dose-response association was estimated using generalized least squares regression with and without restricted cubic spline terms for number of drinks consumed per week. Of 2,164 articles identified, 24 were eligible for inclusion. Meta-analysis of data from 231,808 pregnant women finds those exposed to alcohol during pregnancy have a greater risk of miscarriage compared to those who abstained (odds ratio [OR] 1.19, 95% confidence intervals [CI] 1.12, 1.28). Estimates did not vary by study design, study country, or method of alcohol ascertainment. For alcohol use of 5 or fewer drinks per week, each additional drink per week was associated with a 6% increase in miscarriage risk (OR 1.06, 95% CI 1.01, 1.10). Common study limitations reflect challenges inherent to this research, including difficulty recruiting participants early enough in pregnancy to observe miscarriage and collecting and quantifying information about alcohol consumption during pregnancy that accurately reflects use. This review provides evidence that alcohol consumption during pregnancy is associated with a dose-mediated increase in miscarriage risk. Future studies evaluating change in alcohol use in pregnancy are needed to provide insight into how alcohol consumption prior to pregnancy recognition impacts risk.
Topics: Abortion, Spontaneous; Alcohol Drinking; Dose-Response Relationship, Drug; Female; Humans; Pregnancy
PubMed: 31194258
DOI: 10.1111/acer.14124 -
Role of maternal age and pregnancy history in risk of miscarriage: prospective register based study.BMJ (Clinical Research Ed.) Mar 2019To estimate the burden of miscarriage in the Norwegian population and to evaluate the associations with maternal age and pregnancy history.
OBJECTIVES
To estimate the burden of miscarriage in the Norwegian population and to evaluate the associations with maternal age and pregnancy history.
DESIGN
Prospective register based study.
SETTING
Medical Birth Register of Norway, the Norwegian Patient Register, and the induced abortion register.
PARTICIPANTS
All Norwegian women that were pregnant between 2009-13.
MAIN OUTCOME MEASURE
Risk of miscarriage according to the woman's age and pregnancy history estimated by logistic regression.
RESULTS
There were 421 201 pregnancies during the study period. The risk of miscarriage was lowest in women aged 25-29 (10%), and rose rapidly after age 30, reaching 53% in women aged 45 and over. There was a strong recurrence risk of miscarriage, with age adjusted odds ratios of 1.54 (95% confidence interval 1.48 to 1.60) after one miscarriage, 2.21 (2.03 to 2.41) after two, and 3.97 (3.29 to 4.78) after three consecutive miscarriages. The risk of miscarriage was modestly increased if the previous birth ended in a preterm delivery (adjusted odds ratio 1.22, 95% confidence interval 1.12 to 1.29), stillbirth (1.30, 1.11 to 1.53), caesarean section (1.16, 1.12 to 1.21), or if the woman had gestational diabetes in the previous pregnancy (1.19, 1.05 to 1.36). The risk of miscarriage was slightly higher in women who themselves had been small for gestational age (1.08, 1.04 to 1.13).
CONCLUSIONS
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.
Topics: Abortion, Habitual; Abortion, Spontaneous; Adult; Age Factors; Female; Humans; Maternal Age; Middle Aged; Norway; Pregnancy; Pregnancy Outcome; Premature Birth; Prospective Studies; Recurrence; Registries; Reproductive History; Risk Assessment; Risk Factors; Stillbirth; Young Adult
PubMed: 30894356
DOI: 10.1136/bmj.l869 -
The Cochrane Database of Systematic... Apr 2021Miscarriage, defined as the spontaneous loss of a pregnancy before 24 weeks' gestation, is common with approximately 25% of women experiencing a miscarriage in their... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Miscarriage, defined as the spontaneous loss of a pregnancy before 24 weeks' gestation, is common with approximately 25% of women experiencing a miscarriage in their lifetime, and 15% to 20% of pregnancies ending in a miscarriage. Progesterone has an important role in maintaining a pregnancy, and supplementation with different progestogens in early pregnancy has been attempted to rescue a pregnancy in women with early pregnancy bleeding (threatened miscarriage), and to prevent miscarriages in asymptomatic women who have a history of three or more previous miscarriages (recurrent miscarriage).
OBJECTIVES
To estimate the relative effectiveness and safety profiles for the different progestogen treatments for threatened and recurrent miscarriage, and provide rankings of the available treatments according to their effectiveness, safety, and side-effect profile.
SEARCH METHODS
We searched the following databases up to 15 December 2020: Cochrane Central Register of Controlled Trials, Ovid MEDLINE(R), ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP), and reference lists of retrieved studies.
SELECTION CRITERIA
We included all randomised controlled trials assessing the effectiveness or safety of progestogen treatment for the prevention of miscarriage. Cluster-randomised trials were eligible for inclusion. Randomised trials published only as abstracts were eligible if sufficient information could be retrieved. We excluded quasi- and non-randomised trials.
DATA COLLECTION AND ANALYSIS
At least two review authors independently assessed the trials for inclusion and risk of bias, extracted data and checked them for accuracy. We performed pairwise meta-analyses and indirect comparisons, where possible, to determine the relative effects of all available treatments, but due to the limited number of included studies only direct or indirect comparisons were possible. We estimated the relative effects for the primary outcome of live birth and the secondary outcomes including miscarriage (< 24 weeks of gestation), preterm birth (< 37 weeks of gestation), stillbirth, ectopic pregnancy, congenital abnormalities, and adverse drug events. Relative effects for all outcomes are reported separately by the type of miscarriage (threatened and recurrent miscarriage). We used the GRADE approach to assess the certainty of evidence.
MAIN RESULTS
Our meta-analysis included seven randomised trials involving 5,682 women, and all provided data for meta-analysis. All trials were conducted in hospital settings. Across seven trials (14 treatment arms), the following treatments were used: three arms (21%) used vaginal micronized progesterone; three arms (21%) used dydrogesterone; one arm (7%) used oral micronized progesterone; one arm (7%) used 17-α-hydroxyprogesterone, and six arms (43%) used placebo. Women with threatened miscarriage Based on the relative effects from the pairwise meta-analysis, vaginal micronized progesterone (two trials, 4090 women, risk ratio (RR) 1.03, 95% confidence interval (CI) 1.00 to 1.07, high-certainty evidence), and dydrogesterone (one trial, 406 women, RR 0.98, 95% CI 0.89 to 1.07, moderate-certainty evidence) probably make little or no difference to the live birth rate when compared with placebo for women with threatened miscarriage. No data are available to assess the effectiveness of 17-α-hydroxyprogesterone or oral micronized progesterone for the outcome of live birth in women with threatened miscarriage. The pre-specified subgroup analysis by number of previous miscarriages is only possible for vaginal micronized progesterone in women with threatened miscarriage. In women with no previous miscarriages and early pregnancy bleeding, there is probably little or no improvement in the live birth rate (RR 0.99, 95% CI 0.95 to 1.04, high-certainty evidence) when treated with vaginal micronized progesterone compared to placebo. However, for women with one or more previous miscarriages and early pregnancy bleeding, vaginal micronized progesterone increases the live birth rate compared to placebo (RR 1.08, 95% CI 1.02 to 1.15, high-certainty evidence). Women with recurrent miscarriage Based on the results from one trial (826 women) vaginal micronized progesterone (RR 1.04, 95% CI 0.95 to 1.15, high-certainty evidence) probably makes little or no difference to the live birth rate when compared with placebo for women with recurrent miscarriage. The evidence for dydrogesterone compared with placebo for women with recurrent miscarriage is of very low-certainty evidence, therefore the effects remain unclear. No data are available to assess the effectiveness of 17-α-hydroxyprogesterone or oral micronized progesterone for the outcome of live birth in women with recurrent miscarriage. Additional outcomes All progestogen treatments have a wide range of effects on the other pre-specified outcomes (miscarriage (< 24 weeks of gestation), preterm birth (< 37 weeks of gestation), stillbirth, ectopic pregnancy) in comparison to placebo for both threatened and recurrent miscarriage. Moderate- and low-certainty evidence with a wide range of effects suggests that there is probably no difference in congenital abnormalities and adverse drug events with vaginal micronized progesterone for threatened (congenital abnormalities RR 1.00, 95% CI 0.68 to 1.46, moderate-certainty evidence; adverse drug events RR 1.07 95% CI 0.81 to 1.39, moderate-certainty evidence) or recurrent miscarriage (congenital abnormalities 0.75, 95% CI 0.31 to 1.85, low-certainty evidence; adverse drug events RR 1.46, 95% CI 0.93 to 2.29, moderate-certainty evidence) compared with placebo. There are limited data and very low-certainty evidence on congenital abnormalities and adverse drug events for the other progestogens.
AUTHORS' CONCLUSIONS
The overall available evidence suggests that progestogens probably make little or no difference to live birth rate for women with threatened or recurrent miscarriage. However, vaginal micronized progesterone may increase the live birth rate for women with a history of one or more previous miscarriages and early pregnancy bleeding, with likely no difference in adverse events. There is still uncertainty over the effectiveness and safety of alternative progestogen treatments for threatened and recurrent miscarriage.
Topics: Abortion, Habitual; Abortion, Spontaneous; Bias; Birth Rate; Dydrogesterone; Female; Humans; Hydroxyprogesterones; Live Birth; Network Meta-Analysis; Placebos; Pregnancy; Progesterone; Progestins; Randomized Controlled Trials as Topic; Stillbirth
PubMed: 33872382
DOI: 10.1002/14651858.CD013792.pub2 -
Genes May 2020There is a high incidence of chromosomal abnormalities in early human embryos, whether they are generated by natural conception or by assisted reproductive technologies... (Review)
Review
There is a high incidence of chromosomal abnormalities in early human embryos, whether they are generated by natural conception or by assisted reproductive technologies (ART). Cells with chromosomal copy number deviations or chromosome structural rearrangements can compromise the viability of embryos; much of the naturally low human fecundity as well as low success rates of ART can be ascribed to these cytogenetic defects. Chromosomal anomalies are also responsible for a large proportion of miscarriages and congenital disorders. There is therefore tremendous value in methods that identify embryos containing chromosomal abnormalities before intrauterine transfer to a patient being treated for infertility-the goal being the exclusion of affected embryos in order to improve clinical outcomes. This is the rationale behind preimplantation genetic testing for aneuploidy (PGT-A) and structural rearrangements (-SR). Contemporary methods are capable of much more than detecting whole chromosome abnormalities (e.g., monosomy/trisomy). Technical enhancements and increased resolution and sensitivity permit the identification of chromosomal mosaicism (embryos containing a mix of normal and abnormal cells), as well as the detection of sub-chromosomal abnormalities such as segmental deletions and duplications. Earlier approaches to screening for chromosomal abnormalities yielded a binary result of normal versus abnormal, but the new refinements in the system call for new categories, each with specific clinical outcomes and nuances for clinical management. This review intends to give an overview of PGT-A and -SR, emphasizing recent advances and areas of active development.
Topics: Abortion, Spontaneous; Aneuploidy; Blastocyst; Chromosome Aberrations; Chromosome Disorders; Chromosomes; Humans; Mosaicism; Preimplantation Diagnosis
PubMed: 32485954
DOI: 10.3390/genes11060602 -
Reproductive Sciences (Thousand Oaks,... Dec 2021Recurrent spontaneous abortion affects approximately 1-2% of women of childbearing, and describes a condition in which women suffer from three or more continuous... (Review)
Review
Recurrent spontaneous abortion affects approximately 1-2% of women of childbearing, and describes a condition in which women suffer from three or more continuous spontaneous miscarriages. However, the origin of recurrent spontaneous abortion (RSA) remains unknown, preventing effective treatment and placing stress upon patients. It has been acknowledged that successful pregnancy necessitates balanced immune responses. Therefore, immunological aberrancy may be considered a root cause of poor pregnancy outcomes. Considerable published studies have investigated the relationship between various immune cells and RSA. Here, we review current knowledge on this area, and discuss the five main categories of immune cells involved in RSA; these include innate lymphocytes (ILC), macrophages, decidual dendritic cells (DCs), and T cells. Furthermore, we sought to summarize the impact of the multiple interactions of various immune cells on the emergence of RSA. A good understanding of pregnancy-induced immunological alterations could reveal new therapeutic strategies for favorable pregnancy outcomes.
Topics: Abortion, Habitual; Abortion, Spontaneous; Dendritic Cells; Female; Humans; Immunity, Innate; Macrophages; Pregnancy; T-Lymphocytes
PubMed: 34101149
DOI: 10.1007/s43032-021-00599-y