Selective chromosome analysis in couples with two or more miscarriages: case-control study

Prevalence of karyotype alterations in couples with recurrent pregnancy loss in a tertiary center in Brazil

Objective

To assess the prevalence and type of chromosomal abnormalities in Brazilian couples with recurrent pregnancy loss (RPL) and compare the clinical characteristics of couples with and without chromosome abnormalities.

Methods

We assessed the medical records of 127 couples with a history of two or more miscarriages, referred to a tertiary academic hospital in Belo Horizonte, Brazil, from January 2014 to May 2023. Karyotype was generated from peripheral blood lymphocyte cultures, and cytogenetic analysis was performed according to standard protocols by heat-denatured Giemsa (RHG) banding.

Results

Abnormal karyotypes were detected in 10 couples (7.8%). The prevalence of chromosomal abnormalities was higher among females (6.3%) compared to males (2.0%), but this difference was not statistically significant (p=0.192). The mean number of miscarriages was. 3.3 ± 1.1 in couples with chromosome abnormalities and 3.1 ± 1.5 in couples without chromosome abnormalities (p=0.681). Numerical chromosomal anomalies (6 cases) were more frequent than structural anomalies. Four women presented low-grade Turner mosaicism. No differences were found between couples with and without karyotype alterations, except for maternal age, which was higher in the group with chromosome alterations.

Conclusion

The prevalence of parental chromosomal alterations in our study was higher than in most series described in the literature and was associated with increased maternal age. These findings suggest that karyotyping should be part of the investigation for Brazilian couples with RPL, as identifying the genetic etiology may have implications for subsequent pregnancies.

Australasian Recurrent Pregnancy Loss Clinical Management Guideline 2024 Part I

Guidelines for the investigation and management of recurrent pregnancy loss (RPL) have been developed in Europe, USA and UK, but there is currently no Australasian guideline. The Australasian Certificate of Reproductive Endocrinology and Infertility Consensus Expert Panel on Trial Evidence group has prepared a two-part guideline to provide guidance on the management of RPL. In Part I chromosomal, anatomical, and endocrine factors are outlined along with relevant recommendations for clinical management, levels of evidence and grades of consensus. In Part II thrombophilia, autoimmune factors, infective, inflammatory, and endometrial causes, environmental and lifestyle factors, male factor and unexplained causes will be outlined.

Managing couples with recurrent miscarriage: A narrative review and practice recommendations

There is significant variation in practice when managing couples with recurrent miscarriage (RM), with guidelines differing on the definition of RM, recommended investigations, and treatment options. In the absence of evidence-based guidance, and following on from a paper by the authors-FIGO Good Practice Recommendations on the use of progesterone in the management of recurrent first-trimester miscarriage-this narrative review aims to propose a global holistic approach. We present graded recommendations based on best available evidence.

Identifying discrepancies between clinical practice and evidence-based guideline in recurrent pregnancy loss care, a tool for clinical guideline implementation

BACKGROUND

Practice variation in recurrent pregnancy loss (RPL) care is common. International guidelines vary in their recommendations for the management of RPL couples, which could lead to an increase of cross border reproductive care. Currently, the Dutch RPL guideline is being adapted from the European Society for Human Reproduction and Embryology (ESHRE) guideline. We aim to identify discrepancies between RPL guidelines and RPL practice. These discrepancies could be considered in the development of a new guideline and implementation strategies to promote adherence to new recommendations.

METHODS

A nationwide survey on the management of RPL patients was conducted across all 107 hospital-based obstetrics and gynaecology practices in the Netherlands. The survey was sent via the Dutch Society for Obstetricians and Gynaecologists to all affiliated clinicians. The questionnaire consisted of 36 questions divided in four sections: clinician's demographics, RPL definition, investigations and therapy. The data were compared to the recommendations given by the Dutch national guideline and the most recent guideline of the ESHRE.

RESULTS

All hospital-based practices (100%; n = 107) filled in the online questionnaire. The majority of respondents defined RPL similarly, as two or more pregnancy losses (87.4%), not obligatory consecutive (93.1%). More than half of respondents routinely perform thrombophilia screening ( 58%), although not advised by the ESHRE, while thyroid function (57%), thyroid auto-immunity (27%) and β2-glycoprotein antibodies (42%) in the context of antiphospholipid syndrome (APS) are recommended but investigated less often. Regarding parental karyotyping, 20% of respondents stated they always perform parental karyotyping, without prior risk assessment. because of RPL. Treatment for hereditary thrombophilia was frequently (43.8% (n = 137)) prescribed although not recommended. And finally, a considerable part (12-16%) of respondents prescribe medication in case of unexplained RPL.

CONCLUSION

While many clinicians perform investigations recommended by the ESHRE, there is a considerable variation of RPL practice in the Netherlands. We identified discrepancies between RPL guidelines and RPL practice, providing possibilities to focus on multifaceted implementation strategies, such as educational intervention, local consensus processes and auditing and feedback. This will improve the quality of care provided to RPL patients and may diminish the necessity felt by patients to turn to multiple opinions or cross border reproductive care.

Investigating the "Fetal Side" in Recurrent Pregnancy Loss: Reliability of Cell-Free DNA Testing in Detecting Chromosomal Abnormalities of Miscarriage Tissue

(1) Background: The aim of our study is to evaluate whether cell-free DNA testing can overlap the genetic testing of miscarriage tissue in women with early pregnancy loss (EPL) and length of recurrent pregnancy loss (RPL); (2) Methods: We conducted a prospective cohort study at the Pregnancy Loss Unit of the Fondazione Policlinico Universitario A. Gemelli (IRCCS), Rome, Italy between May 2021 and March 2022. We included women with EPL and length of RPL. Gestational age was >9 weeks + 2 days and <12 weeks + 0 days of gestation corresponding to a crown rump length measurement of >25 and <54 mm. Women underwent both dilation and curettage for the collection of miscarriage tissue and for blood sample collection. Chromosomal microarray analysis (CMA) on miscarriage tissues was performed by oligo-nucleotide- and single nucleotide polymorphisms (SNP)-based comparative genomic hybridization (CGH+SNP). Maternal blood samples were analyzed by Illumina VeriSeq non-invasive prenatal testing (NIPT) to evaluate the cell-free fetal DNA (cfDNA) and the corresponding fetal fraction and the presence of genetic abnormalities; (3) Results: CMA on miscarriage tissues revealed chromosome aneuploidies in 6/10 cases (60%), consisting of trisomy 21 (5 cases) and monosomy X (one case). cfDNA analysis was able to identify all cases of trisomy 21. It failed to detect monosomy X. A large 7p14.1p12.2 deletion concomitant to trisomy 21 was, in one case, detected by cfDNA analysis but it was not confirmed by CMA on miscarriage tissue. (4) Conclusions: cfDNA largely reproduces the chromosomal abnormalities underlying spontaneous miscarriages. However, diagnostic sensitivity of cfDNA analysis is lower with respect to the CMA of miscarriage tissues. In considering the limitations when obtaining biological samples from aborted fetuses suitable for CMA or standard chromosome analysis, cfDNA analysis is a useful, although not exhaustive, tool for the chromosome diagnosis of both early and recurrent pregnancy loss.

Whole-genome sequencing analysis in families with recurrent pregnancy loss: A pilot study

One to two percent of couples suffer recurrent pregnancy loss and over 50% of the cases are unexplained. Whole genome sequencing (WGS) analysis has the potential to identify previously unrecognized causes of pregnancy loss, but few studies have been performed, and none have included DNA from families including parents, losses, and live births. We conducted a pilot WGS study in three families with unexplained recurrent pregnancy loss, including parents, healthy live births, and losses, which included an embryonic loss (<10 weeks' gestation), fetal deaths (10-20 weeks' gestation) and stillbirths (≥ 20 weeks' gestation). We used the Illumina platform for WGS and state-of-the-art protocols to identify single nucleotide variants (SNVs) following various modes of inheritance. We identified 87 SNVs involving 75 genes in embryonic loss (n = 1), 370 SNVs involving 228 genes in fetal death (n = 3), and 122 SNVs involving 122 genes in stillbirth (n = 2). Of these, 22 de novo, 6 inherited autosomal dominant and an X-linked recessive SNVs were pathogenic (probability of being loss-of-function intolerant >0.9), impacting known genes (e.g., DICER1, FBN2, FLT4, HERC1, and TAOK1) involved in embryonic/fetal development and congenital abnormalities. Further, we identified inherited missense compound heterozygous SNVs impacting genes (e.g., VWA5B2) in two fetal death samples. The variants were not identified as compound heterozygous SNVs in live births and population controls, providing evidence for haplosufficient genes relevant to pregnancy loss. In this pilot study, we provide evidence for de novo and inherited SNVs relevant to pregnancy loss. Our findings provide justification for conducting WGS using larger numbers of families and warrant validation by targeted sequencing to ascertain causal variants. Elucidating genes causing pregnancy loss may facilitate the development of risk stratification strategies and novel therapeutics.

Genetische Diagnostik bei ungewollt kinderlosen Paaren oder wiederholten Fehlgeburten

Etwa 10–15 % aller Paare sind ungewollt kinderlos, entweder durch das fehlende Eintreten einer Schwangerschaft oder durch rezidivierende Aborte. Nachweisbare Ursachen einer Fertilitätsstörung finden sich gleichermaßen bei Männern und bei Frauen, bei einem Drittel sind beide Partner beteiligt. Bei 5–10 % der weiblichen und 10–20 % der männlichen Patienten sind mit den derzeit etablierten diagnostischen Analysen genetische Ursachen erkennbar. Eine ätiologische Abklärung erlaubt eine fundierte Prognose und manchmal eine spezifische Therapie, sie kann auf ein erhöhtes Risiko des Auftretens kindlicher Erkrankungen hinweisen. Eine spezifische genetische Abklärung ist daher unabhängig von einer gegebenenfalls geplanten reproduktionsmedizinischen Behandlung bei allen Paaren indiziert, die länger als ein Jahr vergeblich versuchen, ein Kind zu bekommen, und bei denen keine andere Erklärung für eine Unfruchtbarkeit nachgewiesen wurde. Die genetische Diagnostik der Unfruchtbarkeit umfasst bei beiden Partnern in der Regel eine klassische Karyotypisierung zum Nachweis einer gegebenenfalls vorliegenden gonosomalen oder balancierten strukturellen Chromosomenveränderung. Dies ist insbesondere beim wiederholten Auftreten von Fehlgeburten bei beiden Partnern indiziert. Abhängig von hormonellen Befunden sollte bei Frauen ein attenuiertes adrenogenitales Syndrom bzw. bei Verdacht auf eine primäre Ovarialinsuffizienz eine FMR1-Prämutation ausgeschlossen werden. Die genetische Diagnostik des Mannes bei Azoospermie oder gegebenenfalls bei schwerer Oligozoospermie umfasst zusätzlich zur Karyotypisierung die Testung auf AZF-Mikrodeletionen (AZF Azoospermiefaktor) sowie in Abhängigkeit von den klinischen Parametern auf pathogene Varianten im CFTR-Gen als mögliche Ursache einer obstruktiven Azoospermie. Sequenzanalysen spezifischer Gene können bei Frauen und Männern mit hypogonadotropem Hypogonadismus oder bei Verdacht auf eine monogene Spermatogenesestörung in Betracht gezogen werden. Gemäß den Leitlinien und nationalen gesetzlichen Grundlagen sollten vor der genetischen Diagnostik sowie beim Nachweis genetischer Ursachen einer Infertilität mögliche Konsequenzen und die Bedeutung für zukünftige Kinder im Rahmen einer genetischen Beratung besprochen werden.

A Retrospective Assessment of Thrombophilia in Pregnant Women with First and Second Trimester Pregnancy Loss

Recurrent Pregnancy Loss (RPL) affects between 1% to 5% of women of reproductive age. It is widely believed that RPL is a complex disorder that is influenced by chromosomal abnormalities, genetic mutations, uterine anatomic deformity, endocrine dysfunction, immunologic factors, infections, and the environment. Thrombotic disorders are a frequent cause of RPL, accounting for almost half of all cases; however, in the rest of the cases, the cause of RPL remains unclear. Therefore, in this study, it was planned to determine the genetic mutations involved in RPL during the first and second trimester of pregnancy. An observational retrospective cohort study was conducted in 2021, collecting data from 157 first trimester miscarriages and 54 s trimester pregnancies. All patients with a panel of laboratory and genetic analysis for thrombophilia were included for data analysis. It was observed that four factors were significantly more prevalent in one of the groups. Factor V Leiden (FVL) homozygosity and antiphospholipid syndrome (APS) antibodies were statistically significantly more common in pregnant women who suffered first trimester pregnancy losses. On the other hand, Protein C deficiency and Glycoprotein Ia polymorphism were statistically significantly more frequent in the second trimester group. The strongest independent risk factors for first trimester pregnancy loss were FVL and prothrombin (PT) compound mutations (OR = 3.11), followed by FVL homozygous mutation (OR = 3.66), and APS antibodies (OR = 4.47). Regarding second trimester pregnancy loss risk factors, the strongest were FVL and PT compound (OR = 3.24), followed by Glycoprotein Ia polymorphism (OR = 3.61), and respectively, APS antibodies (OR = 3.85). Numerous thrombophilic risk factors for early and late pregnancy loss have been found, including several mutations that seem to occur more often either during the first or the second trimester. Even though we are aware of risk-free and efficient diagnostics for thrombophilia abnormalities, no intervention has been proved to be clearly successful after the detection of these variables.

Management of recurrent implantation failure: British Fertility Society policy and practice guideline

Recurrent implantation failure (RIF) is defined as the absence of a positive pregnancy test after three consecutive transfers of good quality embryos. There remains significant variation in clinical practice in the management of RIF. This British Fertility Society (BFS) Policy and Practice guideline analyses the evidence for investigations and therapies that are employed in RIF and provides recommendations for clinical practice and for further research. Evidence for investigations of sperm and egg quality, uterine and adnexal factors, immunological factors and thrombophilia, endocrine conditions and genetic factors and for associated therapies have been evaluated. This guideline has been devised to assist reproductive medicine specialists and patients in making shared decisions concerning management of RIF. Finally, suggestions for research towards improving understanding and management of RIF have also been provided.

The pattern of chromosomal abnormalities in recurrent miscarriages: a single center retrospective study

BACKGROUND

Chromosomal abnormalities are more common in first trimester recurrent miscarriages (RM). Chromosomal anomalies affect approximately 2%-8% of couples with RM.

OBJECTIVES

Evaluate the spectrum and the frequencies of chromosomal anomalies in RM.

DESIGN

A retrospective hospital record-based descriptive study.

SETTING

A tertiary care center in Turkey.

PATIENTS AND METHODS

We studied couples with RM between October 2020 and January 2022. Relevant family and medical history, clinical examination and the results of karyotype were statistically analyzed.

MAIN OUTCOME MEASURES

Prevalence and types of chromosomal aberrations in couples with RM. SAMPLE SİZE: 362 couples with a history of RM RESULTS: Among the 362 couples, 14 cases (3.86%) had chromosome abnormalities. Eight cases (57.14%) were structural anomalies and six cases (42.86%) were numerical chromosomal aberrations. We found five balanced translocations (67.5%) and three Robertsonian translocations (37.5%). The prevalence of polymorphic variants was 51/362 (14.1%).

CONCLUSIONS

This study supports the conclusion that clinicians should understand the importance of chromosome analysis in these couples and direct them to karyotyping after two abortions in order to exclude the possibility of a genetic cause of RM.

LIMITATIONS

Single-center study and retrospective.

CONFLICT OF INTEREST

None.

External validation of a frequently used prediction model for ongoing pregnancy in couples with unexplained recurrent pregnancy loss

STUDY QUESTION

What is the predictive performance of a currently recommended prediction model in an external Dutch cohort of couples with unexplained recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

The model shows poor predictive performance on a new population; it overestimates, predicts too extremely and has a poor discriminative ability.

WHAT IS KNOWN ALREADY

In 50-75% of couples with RPL, no risk factor or cause can be determined and RPL remains unexplained. Clinical management in RPL is primarily focused on providing supportive care, in which counselling on prognosis is a main pillar. A frequently used prediction model for unexplained RPL, developed by Brigham et al. in 1999, estimates the chance of a successful pregnancy based on number of previous pregnancy losses and maternal age. This prediction model has never been externally validated.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study consisted of 739 couples with unexplained RPL who visited the RPL clinic of the Leiden University Medical Centre between 2004 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Unexplained RPL was defined as the loss of two or more pregnancies before 24 weeks, without the presence of an identifiable cause for the pregnancy losses, according to the ESHRE guideline. Obstetrical history and maternal age were noted at intake at the RPL clinic. The outcome of the first pregnancy after intake was documented. The performance of Brigham's model was evaluated through calibration and discrimination, in which the predicted pregnancy rates were compared to the observed pregnancy rates.

MAIN RESULTS AND THE ROLE OF CHANCE

The cohort included 739 women with a mean age of 33.1 years (±4.7 years) and with a median of three pregnancy losses at intake (range 2-10). The mean predicted pregnancy success rate was 9.8 percentage points higher in the Brigham model than the observed pregnancy success rate in the dataset (73.9% vs 64.0% (95% CI for the 9.8% difference 6.3-13.3%)). Calibration showed overestimation of the model and too extreme predictions, with a negative calibration intercept of -0.46 (95% CI -0.62 to -0.31) and a calibration slope of 0.42 (95% CI 0.11-0.73). The discriminative ability of the model was very low with a concordance statistic of 0.55 (95% CI 0.51-0.59). Recalibration of the Brigham model hardly improved the c-statistic (0.57; 95% CI 0.53-0.62).

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study in which only the first pregnancy after intake was registered. There was no time frame as inclusion criterium, which is of importance in the counselling of couples with unexplained RPL. Only cases with a known pregnancy outcome were included.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study externally validating the Brigham prognostic model that estimates the chance of a successful pregnancy in couples with unexplained RPL. The results show that the frequently used model overestimates the chances of a successful pregnancy, that predictions are too extreme on both the high and low ends and that they are not much more discriminative than random luck. There is a need for revising the prediction model to estimate the chance of a successful pregnancy in couples with unexplained RPL more accurately.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was used and no competing interests were declared.

TRIAL REGISTRATION NUMBER

N/A.

Toward more accurate prediction of future pregnancy outcome in couples with unexplained recurrent pregnancy loss: taking both partners into account

OBJECTIVE

To identify, besides maternal age and the number of previous pregnancy losses, additional characteristics of couples with unexplained recurrent pregnancy loss (RPL) that improve the prediction of an ongoing pregnancy.

DESIGN

Hospital-based cohort study in couples who visited specialized RPL units of two academic centers between 2012 and 2020.

SETTING

Two academic centers in the Netherlands.

PATIENTS

Clinical data from 526 couples with unexplained RPL were used in this study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURES

The final model to estimate the chance of a subsequent ongoing pregnancy was determined using a backward selection process and internally validated using bootstrapping. Model performance was assessed in terms of calibration and discrimination (area under the receiver operating characteristic curve).

RESULTS

Subsequent ongoing pregnancy was achieved in 345 of 526 couples (66%). The number of previous pregnancy losses, maternal age, paternal age, maternal body mass index, paternal body mass index, maternal smoking status, and previous in vitro fertilization/intracytoplasmic sperm injection treatment were predictive of the outcome. The optimism-corrected area under the receiver operating characteristic curve was 0.63 compared with 0.57 when using only the number of previous pregnancy losses and maternal age.

CONCLUSIONS

The identification of additional predictors of a subsequent ongoing pregnancy after RPL, including male characteristics, is significant for both clinicians and couples with RPL. At the same time, we showed that the predictive ability of the current model is still limited and more research is warranted to develop a model that can be used in clinical practice.

Low molecular weight heparin or LMWH plus aspirin in the treatment of unexplained recurrent miscarriage with negative antiphospholipid antibodies: A meta-analysis of randomized controlled trial

OBJECTIVE

Unexplained recurrent miscarriage (uRM) has caused serious distress to women of childbearing age, and effective treatment is particularly important. The aim of this meta-analysis is to compare the efficacy of low molecular weight heparin (LMWH) and LMWH combined with aspirin for uRM.

METHODS

Databases including PubMed, Web of Science, Embase, Scopus and the Cochrane Library databases were electronically searched to identify randomized controlled trials that reported the LMWH or LMWH combined with aspirin for women with uRM and negative antiphospholipid antibodies (aPL). The retrieval time is limited from inception to June 2021. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed by using STATA 12.0 software.

RESULTS

A total of 7 studies involving 1849 patients were included. The meta-analysis results showed that compared with the control group, both LMWH and LMWH + aspirin interventions showed no substantial influence on miscarriage rate (LMWH: RR = 0.69, 95%CI: 0.34-1.39, P = 0.293, LMWH + aspirin: RR = 0.62, 95%CI: 0.30-1.27, P = 0.19) and the occurrence of pre-eclampsia (LMWH: RR = 1.1, 95%CI: 0.53-2.31, P = 0.792; LMWH + aspirin: RR = 1.49, 95%CI: 0.25-8.79, P = 0.662). LMWH therapy had no influence on the live births (RR = 0.99, 95%CI: 0.92-1.06, P = 0.72). Subgroup analysis showed that enoxaparin is not effective in women with uRM and negative aPL (miscarriage rate: RR = 0.82, 95%CI: 0.31-2.19, P = 0.695; pre-eclampsia: RR = 1.03, 95%CI: 0.46-2.33, P = 0.936).

CONCLUSIONS

LMWH and LMWH combined with aspirin therapy cannot improve the pregnancy outcome of women with uRM and negative aPL. However, the above conclusions are still required to be verified through more RCTs due to the limited quantity of included studies.

Assessment of DNA damage in relation to heavy metal induced oxidative stress in females with recurrent pregnancy loss (RPL)

Pregnancy termination consecutively for three or more times during the first trimester is termed as Recurrent pregnancy loss (RPL). In addition to the abnormal karyotype, heavy metal induced oxidative damage may contribute as prominent etiological factor in pregnancy termination. Oxidative stress is considered crucial in etiology underlying RPL with altered antioxidant status and subsequent DNA damage. The current case controlled study investigated Total antioxidant capacity (TAC), DNA damage (8OHdG) and heavy metals in RPL group (n = 30) and the women with successful pregnancies and no cases of miscarriage as control group (30 women). Heavy metals -Antimony (Sb) and Arsenic (As) were measured by Inductively Coupled Plasma Mass spectrophotometry (ICP-MS). There was significant decrease in levels of TAC in RPL group compared to healthy pregnant women (P < 0.05). On contrary, elevated levels of As and Sb were observed in RPL group with subsequent increase in the levels of 8OHdG (P < 0.001); indicating extensive DNA damage in these patients. Furthermore, increased levels of As and Sb in RPL group were positively correlated with 8OHdG and negatively with total antioxidant capacity. The outcome of the study provides clear insight of the role of metal induced oxidative stress that plays a vital role in the pathophysiology underlying RPL.

Role of low-molecular-weight heparin in altering uterine artery blood flow in recurrent spontaneous abortion: a prospective study

OBJECTIVE

This study aimed to determine the role of uterine artery blood flow (UABF) in recurrent spontaneous abortion (RSA) and to determine a viable option to promote the outcome of pregnancy.

METHODS

A total of 421 women were prospectively recruited for this research. UABF indices, including the systolic/diastolic ratio, pulsatility index and resistance index, during the midluteal phase were compared between patients with RSA and women without RSA (controls). After low-molecular-weight heparin (LMWH) was administered to patients with RSA, indices at 7, 10, and 12 weeks of gestation were compared between the two groups.

RESULTS

UABF indices during the midluteal phase were significantly higher in the RSA group than in the control group. After LMWH was administered to the RSA group, UABF indices in the first trimester were similar to those in the control group. The rate of spontaneous miscarriage was also similar between the groups after LMWH treatment.

CONCLUSIONS

Our study shows that sufficient uterine perfusion is crucial for a successful pregnancy. LMWH reduces the rate of spontaneous miscarriage in patients with RSA to a similar rate in women without RSA. LMWH might play a role in decreasing UABF resistance and increasing uterine perfusion.

Maternal germline factors associated with aneuploid pregnancy loss: a systematic review

BACKGROUND

Miscarriage describes the spontaneous loss of pregnancy before the threshold of viability; the vast majority occur before 12 weeks of gestation. Miscarriage affects one in four couples and is the most common complication of pregnancy. Chromosomal abnormalities of the embryo are identified in ∼50% of first trimester miscarriages; aneuploidy accounts for 86% of these cases. The majority of trisomic miscarriages are of maternal origin with errors occurring during meiotic division of the oocytes. Chromosome segregation errors in oocytes may be sporadic events secondary to advancing maternal age; however, there is increasing evidence to suggest possible maternal germline contributions to this.

OBJECTIVE AND RATIONALE

The objective of this review was to appraise critically the existing evidence relating to maternal germline factors associated with pregnancy loss secondary to embryo aneuploidy, identify limitations in the current evidence base and establish areas requiring further research.

SEARCH METHODS

The initial literature search was performed in September 2019 and updated in January 2021 using the electronic databases OVID MEDLINE, EMBASE and the Cochrane Library. No time or language restrictions were applied to the searches and only primary research was included. Participants were women who had suffered pregnancy loss secondary to numerical chromosomal abnormalities of the embryo. Study identification and subsequent data extraction were performed by two authors independently. The Newcastle-Ottawa Scale was used to judge the quality of the included studies. The results were synthesized narratively.

OUTCOMES

The literature search identified 2198 titles once duplicates were removed, of which 21 were eligible for inclusion in this systematic review. They reported on maternal germline factors having variable degrees of association with pregnancy loss of aneuploid origin. The Online Mendelian Inheritance in Man (OMIM) gene ontology database was used as a reference to establish the functional role currently attributed to the genes reported. The majority of the cases reported and included were secondary to the inheritance of maternal structural factors such as Robertsonian translocations, deletions and insertions. Germline factors with a plausible role in aneuploid pregnancy loss of maternal origin included skewed X-inactivation and CGG repeats in the fragile X mental retardation (FMR1) gene. Studies that reported the association of single gene mutations with aneuploid pregnancy loss were conflicting. Single gene mutations with an uncertain or no role in aneuploid pregnancy loss included mutations in synaptonemal complex protein 3 (SYCP3), mitotic polo-like kinase 4 (PLK4) and meiotic stromal antigen 3 (STAG3) spindle integrity variants and 5,10-methylenetetrahydrofolate reductase (MTHFR).

WIDER IMPLICATIONS

Identifying maternal genetic factors associated with an increased risk of aneuploidy will expand our understanding of cell division, non-disjunction and miscarriage secondary to embryo aneuploidy. The candidate germline factors identified may be incorporated in a screening panel for women suffering miscarriage of aneuploidy aetiology to facilitate counselling for subsequent pregnancies.

Recurrent miscarriage: evidence to accelerate action

Women who have had repeated miscarriages often have uncertainties about the cause, the likelihood of recurrence, the investigations they need, and the treatments that might help. Health-care policy makers and providers have uncertainties about the optimal ways to organise and provide care. For this Series paper, we have developed recommendations for practice from literature reviews, appraisal of guidelines, and a UK-wide consensus conference that was held in December, 2019. Caregivers should individualise care according to the clinical needs and preferences of women and their partners. We define a minimum set of investigations and treatments to be offered to couples who have had recurrent miscarriages, and urge health-care policy makers and providers to make them universally available. The essential investigations include measurements of lupus anticoagulant, anticardiolipin antibodies, thyroid function, and a transvaginal pelvic ultrasound scan. The key treatments to consider are first trimester progesterone administration, levothyroxine in women with subclinical hypothyroidism, and the combination of aspirin and heparin in women with antiphospholipid antibodies. Appropriate screening and care for mental health issues and future obstetric risks, particularly preterm birth, fetal growth restriction, and stillbirth, will need to be incorporated into the care pathway for couples with a history of recurrent miscarriage. We suggest health-care services structure care using a graded model in which women are offered online health-care advice and support, care in a nurse or midwifery-led clinic, and care in a medical consultant-led clinic, according to clinical needs.

Recurrent Spontaneous Miscarriage: a Comparison of International Guidelines

While roughly 30% of all women experience a spontaneous miscarriage in their lifetime, the incidence of recurrent (habitual) spontaneous miscarriage is 1 – 3% depending on the employed definition. The established risk factors include endocrine, anatomical, infection-related, genetic, haemostasis-related and immunological factors. Diagnosis is made more difficult by the sometimes diverging recommendations of the respective international specialist societies. The present study is therefore intended to provide a comparison of existing international guidelines and recommendations. The guidelines of the ESHRE, ASRM, the DGGG/OEGGG/SGGG and the recommendations of the RCOG were analysed. It was shown that investigation is indicated after 2 clinical pregnancies and the diagnosis should be made using a standardised timetable that includes the most frequent causes of spontaneous miscarriage. The guidelines concur that anatomical malformations, antiphospholipid syndrome and thyroid dysfunction should be excluded. Moreover, the guidelines recommend carrying out pre-conception chromosomal analysis of both partners (or of the aborted material). Other risk factors have not been included in the recommendations by all specialist societies, on the one hand because of a lack of diagnostic criteria (luteal phase insufficiency) and on the other hand because of the different age of the guidelines (chronic endometritis). In addition, various economic and consensus aspects in producing the guidelines influence the individual recommendations. An understanding of the underlying decision-making process should lead in practice to the best individual diagnosis and resulting treatment being offered to each couple.

Genetic counseling and diagnostic guidelines for couples with infertility and/or recurrent miscarriage

Around 10-15 % of all couples are infertile, rendering infertility a widespread disease. Male and female causes contribute equally to infertility, and, depending on the definition, roughly 1 % to 5 % of all couples experience recurrent miscarriages. In German-speaking countries, recommendations for infertile couples and couples with recurrent miscarriages are published as consensus-based (S2k) Guidelines by the "Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften" (AWMF). This article summarizes the current recommendations with regard to genetic counseling and diagnostics. Prior to genetic counseling, the infertile couple must undergo a gynecological/andrological examination, which includes anamnesis, hormonal profiling, physical examination and genital ultrasound. Women should be examined for the presence of hyperandrogenemia. Men must further undergo a semen analysis. Based on the overall results, hyper- or hypogonadotropic hypogonadism can be diagnosed in both sexes. Female genetic diagnostics for infertility comprise karyotyping, analysis of the FMR1 premutation and a gene panel including genes associated with congenital hypogonadotropic hypogonadism (CHH) or congenital adrenal hyperplasia. Male genetic diagnostics for infertility comprise karyotyping, screening for AZF microdeletions, CFTR analysis and a gene panel including genes associated with CHH. Also, gene panels are increasingly being used to causally clarify specific phenotypes such as defective sperm morphology/motility or azoospermia. As infertile couples have an increased risk for chromosomal aberrations, a chromosomal analysis should also be offered to both partners prior to undergoing assisted reproductive technology. In couples with recurrent miscarriages, karyotyping is recommended to detect balanced structural chromosomal aberrations.

Recurrent pregnancy loss: diagnostic workup after two or three pregnancy losses? A systematic review of the literature and meta-analysis

BACKGROUND

Recurrent pregnancy loss (RPL) occurs in 1–3% of all couples trying to conceive. No consensus exists regarding when to perform testing for risk factors in couples with RPL. Some guidelines recommend testing if a patient has had two pregnancy losses whereas others advise to test after three losses.

OBJECTIVE AND RATIONALE

The aim of this systematic review was to evaluate the current evidence on the prevalence of abnormal test results for RPL amongst patients with two versus three or more pregnancy losses. We also aimed to contribute to the debate regarding whether the investigations for RPL should take place after two or three or more pregnancy losses.

SEARCH METHODS

Relevant studies were identified by a systematic search in OVID Medline and EMBASE from inception to March 2019. A search for RPL was combined with a broad search for terms indicative of number of pregnancy losses, screening/testing for pregnancy loss or the prevalence of known risk factors. Meta-analyses were performed in case of adequate clinical and statistical homogeneity. The quality of the studies was assessed using the Newcastle-Ottawa scale.

OUTCOMES

From a total of 1985 identified publications, 21 were included in this systematic review and 19 were suitable for meta-analyses. For uterine abnormalities (seven studies, odds ratio (OR) 1.00, 95% CI 0.79–1.27, I² = 0%) and for antiphospholipid syndrome (three studies, OR 1.04, 95% CI 0.86–1.25, I² = 0%) we found low quality evidence for a lack of a difference in prevalence of abnormal test results between couples with two versus three or more pregnancy losses. We found insufficient evidence of a difference in prevalence of abnormal test results between couples with two versus three or more pregnancy losses for chromosomal abnormalities (10 studies, OR 0.78, 95% CI 0.55–1.10), inherited thrombophilia (five studies) and thyroid disorders (two studies, OR 0.52, 95% CI: 0.06–4.56).

WIDER IMPLICATIONS

A difference in prevalence in uterine abnormalities and antiphospholipid syndrome is unlikely in women with two versus three pregnancy losses. We cannot exclude a difference in prevalence of chromosomal abnormalities, inherited thrombophilia and thyroid disorders following testing after two versus three pregnancy losses. The results of this systematic review may support investigations after two pregnancy losses in couples with RPL, but it should be stressed that additional studies of the prognostic value of test results used in the RPL population are urgently needed. An evidenced-based treatment is not currently available in the majority of cases when abnormal test results are present.

Maternal history of recurrent pregnancy loss and future risk of ophthalmic morbidity in the offspring

OBJECTIVE

The objective of the study was to investigate whether maternal history of recurrent pregnancy loss (RPL) is associated with offspring childhood ophthalmic morbidity.

METHOD

A hospital-based cohort analysis comparing long-term offspring ophthalmic morbidity in women with and without a history of RPL was performed. Ophthalmic morbidity included hospitalizations involving a pre-defined set of ICD-9 codes. Offspring with congenital anomalies, perinatal mortality cases, and multifetal pregnancies were excluded from the analysis. Cumulative morbidity incidence was compared using Kaplan-Meier survival curves, and the risk of long-term ophthalmic morbidity was assessed by Cox proportional hazards model after adjustment for confounders.

RESULTS

During the study period, 242,187 newborns met the inclusion criteria; 5% (12,182) of them were offspring born to mothers with a history of RPL. Ophthalmic morbidity was significantly more common in the RPL group (1.3% vs 0.9%, p < .001, Kaplan-Meier log-rank p < .001). Adjustment for confounders, such as maternal age, gestational age, hypertensive disorders, and maternal diabetes, using Cox regression found that being born to a mother with RPL was independently associated with long-term ophthalmic morbidity (adjusted HR 1.35, 95% CI 1.15-1.59, p < .001).

CONCLUSION

Being born to a mother with RPL is independently associated with an increased risk of ophthalmic morbidity.

Defining recurrent pregnancy loss: associated factors and prognosis in couples with two versus three or more pregnancy losses

RESEARCH QUESTION

The definition of recurrent pregnancy loss (RPL) differs internationally. The European Society of Human Reproduction and Embryology (ESHRE) defines RPL as two or more pregnancy losses. Different definitions lead, however, to different approaches to care for couples with RPL. This study aimed to determine whether the distribution of RPL-associated factors was different in couples with two versus three or more pregnancy losses. If a similar distribution were found, couples with two pregnancy losses should be eligible for the same care pathway as couples with three pregnancy losses.

DESIGN

This single-centre, retrospective cohort study investigated 383 couples included from 2012 to 2016 at the Leiden University Medical Center RPL clinic. Details on age, body mass index, smoking status, number of pregnancy losses, mean time to pregnancy loss and performed investigations were collected. The prevalence of uterine anomalies, antiphospholipid syndrome, hereditary thrombophilia, hyperhomocysteinaemia, chromosomal abnormalities and positive thyroid peroxidase antibodies were compared in couples with two versus three or more pregnancy losses.

RESULTS

No associated factor was found in 71.5% of couples with RPL. This did not differ statistically between couples with two versus three or more pregnancy losses (73.6% versus 70.6%; P = 0.569). The distribution of investigated causes did not differ between the two groups.

CONCLUSIONS

As the distribution of associated factors in couples with two versus three or more pregnancy losses is equal, couples with two pregnancy losses should be eligible for the same care pathway as couples with three. This study supports ESHRE's suggestion of including two pregnancy losses in the definition of RPL.

Before the beginning: the genetic risk of a couple aiming to conceive

Disorders of genetic etiology exist in 2%-3% of live-born infants. Identifying couples with increased susceptibility for offspring with anomalies or genetic disorders is increasingly effective as a result of molecular advances. Preimplantation genetic testing (PGT) with the use of trophectoderm biopsy, 24-chromosome testing, and molecular testing have allowed wider applicability for avoiding a clinical pregnancy termination. Cell-free DNA in maternal blood is another targeted option, although invasive prenatal genetic diagnosis provides the greatest amount of genetic information. DNA-based methods to detect subtle chromosomal abnormalities are much more sensitive than traditional karyotypes and do not require cultured cells. Aneuploidy and structural chromosomal abnormalities can be readily detected with the use of small amounts of DNA, if necessary amplified, as in PGT. Novel approaches exist for detecting perturbations in single-gene disorders. Not only has the molecular basis for many monogenic disorders been elucidated, but modest costs for DNA sequencing has made testing feasible. As the number of testable genetic disorders has increased, principles underlying screening have advanced. Genetic screening for disorders of high incidence in certain ethnic groups was initiated decades ago; however, limitations exist, and reduction in live-born incidence is not infrequently small. Expanded carrier screening is now offered in panethnic fashion, extending surveillance to couples of mixed ethnicities and involving many more genetic conditions. Targeted gene panels (e.g., adult-onset cancer genes) further increase the number of genetic disorders amenable to screening, often leading to PGT.

Combination of QF-PCR and aCGH is an efficient diagnostic strategy for the detection of chromosome aberrations in recurrent miscarriage

Background

Our aim was to conduct a comprehensive genetic evaluation using the combination of QF‐PCR (quantitative fluorescence polymerase chain reaction) and aCGH (array comparative genomic hybridization) for the detection of the frequency and type of chromosome aberrations in recurrent miscarriage (RM) in the clinical setting.

Methods

This retrospective study was conducted on 73 first‐trimester products of conception (POC) between September 2014 and February 2017. The POCs were collected from 73 women with at least one previous miscarriage and analyzed for chromosomal anomalies using QF‐PCR and aCGH as part of the routine clinical evaluation.

Results

Chromosome aberrations were detected in 52/73 POCs (71.2%), of which 41 (56.2%) were identified by QF‐PCR and an additional 11 (15.1%) by aCGH. Numerical aberrations constituted 92.3% of abnormalities, with trisomies as the most common subtype (72.9%). Causative structural aberrations were found in three samples (5.8%). The frequency of chromosome aberrations was not dependent on the number of previous miscarriages, whereas it significantly increased with advanced maternal age.

Conclusion

Our results confirm that chromosome aberrations are the most common cause of RM and that QF‐PCR and aCGH combination should be included in the routine genetic analysis of POCs of couples with miscarriage.

Increased cardiovascular disease risk in women with a history of recurrent miscarriage

INTRODUCTION

Cardiovascular disease is the leading cause of death in women. Observational studies suggest that women with a history of recurrent miscarriage have an increased risk of cardiovascular disease.

MATERIAL AND METHODS

Women who visited the recurrent miscarriage clinic at Leiden University Medical Center between 2000 and 2010 and who had their third consecutive miscarriage before the age of 31 years, were invited to participate in this follow-up study (between 2012 and 2014). The reference group consisted of women with at least one uncomplicated pregnancy and no miscarriage, matched by zip code, age, and date of pregnancy. All women were invited for risk factor screening, including physical examination and blood collection. Main outcome measures were the (extrapolated) 10- and 30-year cardiovascular risk scores using the Framingham risk score. A subanalysis was performed for women with idiopathic recurrent miscarriage.

RESULTS

Thirty-six women were included in both groups. Mean follow up was 7.5 years. Women with recurrent miscarriage had a significantly higher extrapolated 10-year cardiovascular risk score (mean 6.24%, SD 5.44) compared with women with no miscarriage (mean 3.56%, SD 1.82, P = .007) and a significantly higher 30-year cardiovascular risk score (mean 9.86%, SD 9.10) compared with women with no miscarriage (mean 6.39%, SD 4.20, P = .04). Similar results were found in women with idiopathic recurrent miscarriage (n = 28).

CONCLUSIONS

Women with a history of recurrent miscarriage differ in cardiovascular risk profile at a young age compared with women with no miscarriage. The findings support an opportunity to identify women at risk of cardiovascular disease later in life and a possible moment for intervention.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/050)

Purpose

Official guideline of the German Society of Gynecology and Obstetrics (DGGG), the Austrian Society of Gynecology and Obstetrics (ÖGGG) and the Swiss Society of Gynecology and Obstetrics (SGGG). The aim of this guideline was to standardize the diagnosis and treatment of couples with recurrent miscarriage (RM). Recommendations were based on the current literature and the views of the involved committee members.

Methods

Based on the current literature, the committee members developed the statements and recommendations of this guideline in a formalized process which included DELPHI rounds and a formal consensus meeting.

Recommendations

Recommendations for the diagnosis and treatment of patients with RM were compiled based on the international literature. Specific established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders were taken into consideration.

ESHRE guideline: recurrent pregnancy loss

STUDY QUESTION

What is the recommended management of women with recurrent pregnancy loss (RPL) based on the best available evidence in the literature?

SUMMARY ANSWER

The guideline development group formulated 77 recommendations answering 18 key questions on investigations and treatments for RPL, and on how care should be organized.

WHAT IS KNOWN ALREADY

A previous guideline for the investigation and medical treatment of recurrent miscarriage was published in 2006 and is in need of an update.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for development of ESHRE guidelines. After formulation of key questions by a group of experts, literature searches and assessments were performed. Papers published up to 31 March 2017 and written in English were included. Cumulative live birth rate, live birth rate and pregnancy loss rate (or miscarriage rate) were considered the critical outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the collected evidence, recommendations were formulated and discussed until consensus was reached within the guideline group. A stakeholder review was organized after finalization of the draft. The final version was approved by the guideline group and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

The guideline provides 38 recommendations on risk factors, prevention and investigations in couples with RPL, and 39 recommendations on treatments. These include 60 evidence-based recommendations – of which 31 were formulated as strong recommendations and 29 as conditional – and 17 good practice points. The evidence supporting investigations and treatment of couples with RPL is limited and of moderate quality. Of the evidence-based recommendations, only 10 (16.3%) were supported by moderate quality evidence. The remaining recommendations were supported by low (35 recommendations: 57.4%), or very low quality evidence (16 recommendations: 26.2%). There were no recommendations based on high quality evidence. Owing to the lack of evidence-based investigations and treatments in RPL care, the guideline also clearly mentions investigations and treatments that should not be used for couples with RPL.

LIMITATIONS, REASONS FOR CAUTION

Several investigations and treatments are offered to couples with RPL, but most of them are not well studied. For most of these investigations and treatments, a recommendation against the intervention or treatment was formulated based on insufficient evidence. Future studies may require these recommendations to be revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in RPL, based on the best evidence available. In addition, a list of research recommendations is provided to stimulate further studies in RPL. One of the most important consequences of the limited evidence is the absence of evidence for a definition of RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed and funded by ESHRE, covering expenses associated with the guideline meetings, with the literature searches and with the dissemination of the guideline. The guideline group members did not receive payment. J.E. reports position funding from CARE Fertility. S.L. reports position funding from SpermComet Ltd. S.M. reports research grants, consulting and speaker’s fees from GSK, BMS/Pfizer, Sanquin, Aspen, Bayer and Daiichi Sankyo. S.Q. reports speaker’s fees from Ferring. The other authors report no conflicts of interest.

ESHRE Pages are not externally peer reviewed. This article has been approved by the Executive Committee of ESHRE.

Prevalence of Cytogenetic Anomalies in Couples with Recurrent Miscarriages: A Case-control Study

Background:

About 15%–20% of couples get affected by recurrent miscarriages (RM) and chromosomal abnormality in one partner affects 3%–6% of RM couples.

Aims:

The present study aimed to determine the prevalence of cytogenetic anomalies in couples with RM.

Settings and Design:

A case–control study was undertaken, in which 243 couples who had experienced 2 or >2 miscarriages were investigated for chromosomal abnormalities and compared with 208 healthy, age-matched control couples who had at least one healthy live born and no history of miscarriages.

Material and Methods:

Peripheral blood (PB) lymphocytes were cultured using PB-Max Karyotyping medium (GIBCO) for chromosomal analysis and 20 metaphases were analyzed for each individual.

Statistical Analysis:

Student's t-test was used for statistical evaluation and P < 0.05 was considered statistically significant for all instances.

Results:

The current study revealed 3.1% RM cases showing structural chromosomal aberrations, of which balanced translocations and Robertsonian translocations constituted 66.7% and 26.7% cases, respectively, while inversions constituted 6.7% abnormal RM cases. Polymorphic variations were observed in 1.9% RM patients and 1.2% controls as well. However, the number of abortions were significantly more (P = 0.027) in male carriers of balanced translocations as compared to female carriers in the RM group. There was no significant difference for age (P = 0.539) between RM women and control women.

Conclusions:

Although similar studies exist in literature, our study is the first of its kind from our region that has compared the chromosomal anomalies between the RM group and the control group. We observed 3.1% of balanced translocations and an increased number (though nonsignificant) of polymorphic variations and satellite associations in the RM group as compared to the control group.

De novo Balanced Robertsonian Translocation rob(22;22)(q10;q10) in a Woman with Recurrent Pregnancy Loss: A Rare Case

BACKGROUND

Recurrent pregnancy loss (RPL), one of the most common complications of pregnancy, is responsible for significant emotional distress to the couple desiring to conceive. In almost 50% of the cases, the etiology remains unknown. The frequency of chromosomal structural rearrangements associated with a history of RPL in couples varies between 2% to 8%. Robertsonian translocations (ROBs) have an estimated incidence rate of 1/1000 births, making this type of rearrangement the most common structural chromosomal abnormalities seen in the general population. According to the literature, there are few RPL cases with rob (22;22).

CASE PRESENTATION

This case is a Syrian female offered to the Orient Hospital (Damascus, Syria), having RPL in the first trimester, no fetal malformations, and/or no neonatal death. She had a balanced chromosomal translocation involved the both short arms of chromosome 22. Banding cytogenetics, refined by array-proven multicolor banding (aMCB) revealed a rob (22; 22)(q10;q10). Her husband had a normal karyotype. Interestingly, chromosomal analysis was performed for her other family members and it revealed normal karyotype for all people, which indicates that translocation is of de novo origin. However, the couple did not have any living offspring after seven years of marriage.

CONCLUSION

The present case was a case of RPL occurring due to rob (22;22). However, the rob(22;22)(q10;10) is the cause of recurrent abortions. Couples with the history of RPL should be suggested to do cytogenetic analysis in order to estimate whether they have chromosomal rearrangement. This diagnostic approach is of great significance to figure out what causes RPL.

Etiological evaluation of repeated biochemical pregnancy in infertile couples who have undergone in vitro fertilization

Objective

This study aims to investigate whether there are any notable etiologies for repeated biochemical pregnancy (RBP) and, if so, to compare those etiologies associated with repeated spontaneous abortion in infertile couples who have undergone in vitro fertilization (IVF).

Methods

Forty-four infertile couples who underwent IVF and experienced RBP were included in this study. RBP was defined as more than 2 early pregnancy losses that occurred before the detection of a gestational sac, with ectopic pregnancies specifically excluded by serial serum beta human chorionic gonadotropin evaluation. Forty-three infertile couples who underwent IVF and experienced recurrent spontaneous abortion (RSA) were included as a control group. Karyotype analysis, anatomic evaluation of uterus, endocrine and immunological evaluation were performed. In addition, the number of pregnant women confirmed by 12 weeks' gestation was compared between groups.

Results

Immunological factors (RSA: 20.9% vs. RBP: 29.5%, P=0.361), diminished ovarian reserve (RSA: 10.9% vs. RBP: 17%, P=0.552), and parental chromosomal abnormalities (RSA: 18.6% vs. RBP: 9.1%, P=0.218) were not different between groups. Additionally, the incidence of uterine factors (RSA: 11.6% vs. RBP: 4.6%, P=0.206), unknown cause (RSA: 48.8% vs. RBP: 54.5%, P=0.161), and the pregnancy outcome identified until 12 weeks' gestation (RSA: 46.5% vs. RBP: 38.6%, P=0.520) did not differ between groups.

Conclusion

In the present study, the causes of RBP after IVF were similar to those of RSA. Accordingly, we suggest that efforts should be made to define the etiology of RBP, particularly for infertile couples, and that possible management strategies should be offered.

Assessment of novel cardiovascular biomarkers in women with a history of recurrent miscarriage

OBJECTIVES

A history of recurrent miscarriage is associated with future cardiovascular disease. The aim of this study was to determine novel cardiovascular biomarkers in women with a history of recurrent miscarriage as this might lead to a better understanding of the association.

STUDY DESIGN

Women who visited the recurrent miscarriage clinic at Leiden University Medical Centre (between 2000 and 2010), and had three consecutive miscarriages ≤30 years were invited to participate in this follow-up study (between 2012 and 2014). The reference group consisted of women with at least one uncomplicated pregnancy and a history of no miscarriage, matched on zip code, age, and date of pregnancy.

MAIN OUTCOME MEASURES

Cardiovascular biomarkers were determined, classified into; inflammation (HsCRP, lipoprotein-associated phospholipase A2), thrombosis (homocysteine, folate, anti-cardiolipin antibodies and anti-ß-2-glycoprotein antibodies), lipid metabolism (lipoprotein(a)), renal function (creatinine, microalbuminuria), myocardial damage (N-terminal pro-brain natriuretic peptide, high sensitive TroponineT) and multiple mechanisms (albumin, vitamin D).

RESULTS

In both groups, 36 women were included. Women with recurrent miscarriage had a significantly higher median HsCRP (1.49 mg/L) compared to women with no miscarriage (1.01 mg/L, p = 0.03) and a significantly lower mean albumin (46.0 vs 47.6g/L, p = 0.004) and vitamin D (55.6 vs 75.4nmol/L, p = 0.007), respectively. Differences remained after adjustments for classic cardiovascular risk factors (BMI, smoking, diabetes mellitus, and hypertension).

CONCLUSIONS

Our findings suggest a proinflammatory state in women with a history of recurrent miscarriage, which suggests a less optimal health, compared to women with no miscarriage. More research (observational and intervention) is warranted to investigate the association with vitamin D.

Low-Molecular-Weight Heparin for the Treatment of Unexplained Recurrent Miscarriage With Negative Antiphospholipid Antibodies: A Randomized Controlled Trial

BACKGROUND

Recurrent miscarriage (RM) is one of the most common clinical problems in reproduction with no definite cause in about 50% of the cases. The study aims to evaluate the effect of low-molecular-weight heparin (LMWH) in the treatment of women with RM negatively tested for antiphospholipid antibodies (APAs).

METHODS

An open-labeled registered randomized controlled study (NCT 01608347) included women who attended the outpatient clinic in Assiut Women Health Hospital and Nag-Hamady Central Hospital, Egypt, with 3 or more unexplained RM. Eligible participants were randomly assigned into 2 groups. The study group included 150 patients receiving LMWH (Tinzaparin sodium 4500 IU) subcutaneous daily injection with 500 µg folic acid once daily orally started once positive pregnancy test till the 20th week of gestation. The control group included 150 patients receiving the same dose of folic acid alone. The primary outcome of the study was the rate of continuation of a viable pregnancy after 20 weeks of gestation.

RESULTS

There was no significant difference between both groups as regards age, parity, or number of previous miscarriages. There was a significant increase in women who continued their pregnancy beyond 20 weeks in the study group compared to the control group (73.3% vs 48%, respectively; P = .002). The take-home baby rate was also significantly higher in the LMWH group compared to the control group ( P = .001).

CONCLUSION

Early start of LMWH decreases the incidence of miscarriage in the first 20 weeks of pregnancy in women with unexplained RM negative for APAs.

Higher prevalence of colonization with Gardnerella vaginalis and gram-negative anaerobes in patients with recurrent miscarriage and elevated peripheral natural killer cells

The role of vaginal infections in recurrent miscarriage (RM) is discussed controversially and screening is not recommended in international guidelines. Peripheral and uterine NK cells (pNK, uNK) play an important role in the establishment of a healthy pregnancy and are targets of immune diagnostics in RM patients. The aim of this study was to analyze the composition of the vaginal microbiota in RM patients and to correlate the findings to clinical characteristics as well as NK cell parameters. In total, n=243 RM patients with ≥3 consecutive miscarriages were recruited between 11/2011 and 03/2016. Vaginal swabs were analyzed by microbiological culture. Further, a cervical swab was taken in n=187 patients and the presence of Chlamydia trachomatis was evaluated by a molecular assay. Peripheral blood levels of CD45+CD3-CD56+CD16+ pNK (determined by four-color fluorescence flow cytometry) and CD56+ uNK (uterine biopsy, determined by immunohistochemistry) were analyzed. The prevalence of Gardnerella vaginalis colonization in RM patients was 19.0%, gram-negative anaerobes 20.5%, Candida species 7.9%, group B Streptococcus 11.0% and Enterobacteriaceae 14.8%. Commensal lactobacilli were absent in 14.5% of the women. Chlamydia trachomatis was detected in n=1 case (0.53%). The prevalence of Gardnerella vaginalis and gram-negative anaerobes in RM patients with elevated pNK (>280/μl, n=69) was significantly higher (p=0.012, p=0.04) compared to patients with normal pNK (n=174). In conclusion, RM patients with elevated pNK suffer more often from colonization by Gardnerella vaginalis and gram-negative anaerobes. This might indicate an association between the vaginal microbiota, local inflammation, changes in immune parameters and miscarriage.

Outcome of preimplantation genetic diagnosis using FISH analysis for recurrent miscarriage in low-risk reciprocal translocation carriers

OBJECTIVE

To assess PGD outcome using FISH analysis in couples with a history of recurrent miscarriage associated with a parental carrier of reciprocal translocation.

STUDY DESIGN

Couples in whom one partner was a carrier of a reciprocal translocation and had a history of two or more miscarriages and a low risk of a live born offspring with an unbalanced chromosomal rearrangement, underwent PGD treatment between 2000 and 2012.

RESULTS

91 couples started 171 fresh and 11 frozen PGD cycles. Of the fresh cycles, 162 (95%) reached oocyte retrieval and 107 (63%) had embryo transfer. In 14 cycles (8%), surplus embryos were cryopreserved. Pregnancy was achieved in 52 fresh PGD cycles, leading to 20 miscarriages and 32 live births. Eleven frozen embryo transfer cycles resulted in two miscarriages and three live births. The overall live birth rate was 19% per fresh and frozen PGD cycle started (35/182) and miscarriage rate was 39% per pregnancy (22/57). The cumulative live birth rate was 32% per couple (29/91).

CONCLUSION

After PGD for recurrent miscarriage in low-risk reciprocal translocation carriers, the miscarriage risk remains high and chance of live birth is low. For those translocation carriers, natural conception may be a better option.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG (S1-Level, AWMF Registry No. 015/050, December 2013)

Purpose: Official guideline coordinated and published by the German Society of Gynecology and Obstetrics (DGGG). Aim of the guideline was to standardize the diagnosis and treatment of patients with recurrent miscarriage (RM). Recommendations were proposed, based on the current national and international literature and the experience of the involved physicians. Consistent definitions, objective assessments and standardized therapy were applied. Methods: Members of the different involved societies developed a consensus in an informal process based on the current literature. The consensus was subsequently approved by the heads of the scientific societies. Recommendations: Recommendations for the diagnosis and treatment of patients with RM were compiled which took the importance of established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders into consideration.

Association of plasminogen activator inhibitor-1 and angiotensin converting enzyme polymorphisms with recurrent pregnancy loss in Iranian women

BACKGROUND

Recurrent pregnancy loss (RPL) defined by two or more failed pregnancies before 20 weeks of gestation. Several factors play a role in RPL including thrombophilic conditions which can be influenced by gene polymorphisms. Plasminogen activator inhibitor-1 (PAI-1) and angiotensin converting enzyme (ACE) genes are closely related to fibrinolytic process, embryonic development and pregnancy success.

OBJECTIVE

The aim of this study was to investigate the relationship between RPL and common polymorphisms in ACE and PAI-1 genes.

MATERIALS AND METHODS

In this case control study, 100 women with recurrent abortions (at least two) were selected as cases and 100 healthy women with two or more normal term deliveries without a history of abortion as controls. Total genomic DNA was isolated from blood leukocytes. The status of the PAI-1 4G/5G and ACE (D/I) polymorphism was determined by PCR-RFLP.

RESULTS

Homozygosity for PAI-1 4G polymorphism was seen in 17 cases (17%), and 5 controls (5%) (p=0.006) so patients with homozygote 4G mutation were significantly more prone to RPL in contrast to control group (OR: 4.63, % 95 CI: 1.55-13.84). In addition, 7 patients (7 %), and no one from the control group, were homozygote (I/I) for ACE polymorphism (p=0.034), suggesting no significant associations between ACE D allele or DD genotype and RPL.

CONCLUSION

Considering these results, because 4G/4G polymorphism for PAI-1 gene could be a thrombophilic variant leading to abortion, analysis of this mutation and other susceptibility factors are recommended in patients with RPL.

Patients with idiopathic recurrent miscarriage show higher levels of DR+ activated T-cells that are less responsive to mitogens

In 50% of recurrent miscarriages (RM) the cause remains unknown and standardized immunological diagnosis and treatment of idiopathic RM (iRM) is yet not established. In this prospective case-control study, out of 220 RM patients screened, 97 iRM patients were identified and compared to 26 healthy controls without a previous pregnancy or blood transfusion in order to identify deregulated immunological parameters. Blood levels of lymphocyte subpopulations, cytokines and neopterin were determined by FACS, ELISA, and Luminex technique. Lymphocyte function was studied by in-vitro lympocyte proliferation tests. As compared to controls, patients had significantly higher proportions of activated CD3+DR+, CD4+DR+ and CD8+DR+ lymphocytes, elevated levels of neopterin and a lower in-vitro proliferation of lymphocytes (all p<0.05). Within the iRM patients higher proportions of CD3+DR+ T-lymphocytes correlated with higher proportions and absolute numbers of CD4+DR+ and CD8+DR+ T-lymphocytes and lower CD16+CD56+ NK-cells. Further, it was associated with lower absolute numbers of CD19+ B-lymphocytes, CD3+CD25+ T-lymphocytes and CD45+ total lymphocytes (all p<0.05). In addition we found decreased in-vitro lymphocyte proliferation in iRM patients with high CD3+DR+ T-lymphocytes (p<0.05). In summary patients with iRM showed increased activated T-cells that are less responsive to mitogens in-vitro. The inverse relationship of increased DR but decreased CD25 expression on CD3+ T-cells and the decreased in-vitro proliferation characterize an immunological disorder with similarities to T-cell exhaustion in patients with HIV and cancer. These abnormalities potentially contribute to the pathogenesis of iRM and might be a target for future immunomodulatory therapies.

MicroRNAome in decidua: a new approach to assess the maintenance of pregnancy

OBJECTIVE

To comparatively analyze the human microRNAomes between normal pregnant and miscarriage deciduas by an in-depth sequencing of microRNA (miRNA); and to specifically examine miRNA-199b-5p and serum/glucocorticoid regulated kinase 1 (SGK1) in vivo and in vitro for their possible roles in pregnancy maintenance.

DESIGN

Samples of deciduas from 6-8-week spontaneous miscarriages and normal pregnant women were irrespectively collected and comparatively analyzed by miRNA sequencing. The miR-199b-5p and SGK1 expressions were validated in vivo and in vitro.

SETTING

University research and clinical institutes.

PATIENT(S)

In this experimental study, samples of deciduas were obtained from October 2011 to April 2012 from 29 women with spontaneous miscarriages and 35 normal pregnant women (control group) who underwent pregnancy termination at 6-8 weeks at our university gynecology unit.

INTERVENTION(S)

Endometrial biopsies, cell transfection, and production of an miR-199b-5p transgenic mouse model.

MAIN OUTCOME MEASURE(S)

In-depth sequencing of the miRNAome on human deciduas was performed for statistically significant differences in miRNA expression. Expression levels of SGK1 were detected by quantitative polymerase chain reaction and immunoblotting (Western blot) in vitro while miR-199b-5p is overexpressed or knockdown in miR-199b-5p transgenic mice.

RESULT(S)

Expression of the 1,921 known miRNAs was analyzed in the study. In aborted deciduas, 0.57% of the miRNAs were expressed abundantly (>10,000 transcripts per million) and represented 86.38% of all the miRNA reads. Six miRNAs were down-regulated (let-7a-5p, let-7f-5p, let-7g-5p, let-7e-5p, let-7d-5p, and miR-98), whereas miR-199b-5p was significantly up-regulated. Overexpression or knockdown of miR-199b-5p in HEK293T and Ishikawa cells decreased or increased SGK1 expression. Furthermore, overexpression of miR-199b-5p in human endometrial stromal cells or in transgenic mouse decreased SGK1 expression at the mRNA and protein levels, respectively.

CONCLUSION(S)

Among the miRNAomes, the abundant expression of the let-7 members was decreased in aborted samples, whereas miR-199b-5p expression was consistently increased. A significant inverse correlation was found between miR-199b-5p and SGK1 in vivo and in vitro.

Immune profiling in patients with recurrent miscarriage

The central role of the maternal immune system for successful and disturbed pregnancies such as recurrent miscarriage (RM) is apparent. Recent studies have increased understanding of the complex interaction of the different immunological players and the adaptation of the maternal immune system to the semi-allogeneic embryo. There is growing evidence for immunological abnormalities in RM patients, including autoimmune and allogeneic factors. However, the question remains unsolved whether these changes represent the cause or the consequence of RM. As in half of the RM patients the underlying mechanism remains unknown, further diagnostic methods are urgently needed. Within this review we summarize (recent) literature on the immunological diagnosis in RM patients to find out current trends and to identify potential targets of therapy. As the exact mechanisms of feto-maternal tolerance have not yet been determined we suggest that the immunological diagnosis should be implemented only in well-designed clinical trials in specialized centers to establish a standardized immunological work-up in RM patients.

Recurrent miscarriage in translocation carriers: no differences in clinical characteristics between couples who accept and couples who decline PGD

STUDY QUESTION

Do clinical characteristics of recurrent miscarriage couples with a chromosomal abnormality and who opt for PGD differ from couples that decline PGD after extensive genetic counselling?

SUMMARY ANSWER

No differences in clinical characteristics are identified between recurrent miscarriage couples carrying a structural chromosomal abnormality who opt for PGD compared with those that decline PGD after extensive genetic counselling.

WHAT IS KNOWN ALREADY

Couples who have experienced two or more miscarriages (recurrent miscarriage) are at increased recurrence risk if one of the partners carries a structural chromosomal abnormality. PGD can be offered to avoid (another) miscarriage or pregnancy termination when (invasive) prenatal diagnosis shows an abnormal result. To date, no reports are available that describe reproductive decision-making after genetic counselling on PGD in these specific couples.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study of 294 couples carrying a structural chromosomal abnormality seeking genetic counselling on PGD between 1996 and 2012.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were recurrent miscarriage couples carrying a structural chromosomal abnormality. They had been referred for genetic counselling to the only national licensed PGD centre. Clinical characteristics analysed included couple associated characteristics, characteristics concerning reproductive history and external characteristics such as type of physician that referred the couple for genetic counselling and the clinical geneticist performing the counselling on PGD.

MAIN RESULTS AND THE ROLE OF CHANCE

Of 294 couples referred for counselling on PGD, 26 were not accepted because they did not meet the criteria for IVF-PGD. The remaining cohort of 268 couples consisted of two-thirds female and one-third male carriers. Main PGD indications were reciprocal translocations (83.9%) and Robertsonian translocations (16.7%). Following genetic counselling, 76.9% of included couples chose PGD as their reproductive option, the others declined PGD. Reproductive choice is not influenced by sex of the translocation carrier (P = 0.499), type of chromosomal abnormality (P = 0.346), number of previous miscarriages (P = 0.882), history of termination of pregnancy (TOP) because of an unbalanced fetal karyotype (P = 0.800), referring physician (P = 0.208) or geneticist who performed the counselling (P = 0.410).

LIMITATIONS, REASONS FOR CAUTION

This study only included recurrent miscarriage couples carrying a structural chromosomal abnormality, who were actually referred to a PGD clinic for genetic counselling. We lack information on couples who were not referred for PGD. Some of these patients may not have been informed on PGD at all, while others were not referred for counselling because they did not opt for PGD to start with.

WIDER IMPLICATIONS OF THE FINDINGS

This study shows that reproductive choices in couples with recurrent miscarriage on the basis of a structural chromosomal abnormality are not influenced by characteristics of the couple itself, nor by their obstetric history or external characteristics. These findings suggest that a couples' intrinsic attitude towards PGD treatment is a major factor influencing their reproductive choice. Future research will focus on these personal motives that seem to push reproductive decision-making following genetic counselling in a given direction.

Spontaneous abortion and recurrent miscarriage: A comparison of cytogenetic diagnosis in 250 cases

Objective

The purpose of this study was to determine the frequency and distribution of cytogenetically abnormal miscarriages in couples with spontaneous abortions (SA) or recurrent miscarriages (RM).

Methods

Karyotyping of specimens from 164 abortuses with SA and 86 abortuses with RM was successfully performed according to the standard cytogenetic methods using G-banding technique.

Results

Among the total 164 cases of SA group, 81 (49.4%) were euploid and the rest (83, 50.6%) showed chromosomal abnormalities. In RM(≥2) and RM(≥3) group, 31 (36.0%)/27 (34.6%) cases were euploid and 55 (64.0%)/51(65.4%) cases were abnormal, respectively. A statistically significant difference was found in the rate of cytogenetic abnormality between SA and RM groups (P<0.05). In all groups, women with advanced maternal age (≥35 years) had a higher rate of chromosome anomalies compared with women younger than age 35 (normal:abnormal = 32.4%:67.6% for ≥35 years and 53.8%:46.2% for <35 years in SA; 19.2%:80.8%/21.7%:78.3% for ≥35 years and 43.3%:56.7%/40.0%:60.0% for <35 years in RM(≥2) and RM(≥3), respectively; P<0.05). In SA group, an increase of normal karyotypes was noted with increased gestational age (<10 week, 38.0%; 10-15 week, 53.5%; 16-20 week, 65.7%). In RM group, most of cases were in <10 week and the frequency of trisomies with chromosomes 1 to 10 were increased compared with that of SA.

Conclusion

There was a statistically significant difference in the frequency and distribution of chromosomal abnormalities between SA and RM groups. Our results will provide useful information for diagnosis and genetic counseling of patients with SA or RM.

Aspirin and/or heparin for women with unexplained recurrent miscarriage with or without inherited thrombophilia

BACKGROUND

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the chance of live birth in subsequent pregnancies in women with unexplained recurrent miscarriage, with or without inherited thrombophilia.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2013) and scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on live birth in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin (UFH), and low molecular weight heparin (LMWH) for the prevention of miscarriage. One treatment could be compared with another or with no-treatment (or placebo).

DATA COLLECTION AND ANALYSIS

Two review authors (PJ and SK) assessed the studies for inclusion in the review and extracted the data. If necessary they contacted study authors for more information. We double checked the data.

MAIN RESULTS

Nine studies, including data of 1228 women, were included in the review evaluating the effect of either LMWH (enoxaparin or nadroparin in varying doses) or aspirin or a combination of both, on the chance of live birth in women with recurrent miscarriage, with or without inherited thrombophilia. Studies were heterogeneous with regard to study design and treatment regimen and three studies were considered to be at high risk of bias. Two of these three studies at high risk of bias showed a benefit of one treatment over the other, but in sensitivity analyses (in which studies at high risk of bias were excluded) anticoagulants did not have a beneficial effect on live birth, regardless of which anticoagulant was evaluated (risk ratio (RR) for live birth in women who received aspirin compared to placebo 0.94, (95% confidence interval (CI) 0.80 to 1.11, n = 256), in women who received LMWH compared to aspirin RR 1.08 (95% CI 0.93 to 1.26, n = 239), and in women who received LMWH and aspirin compared to no-treatment RR 1.01 (95% CI 0.87 to 1.16) n = 322).Obstetric complications such as preterm delivery, pre-eclampsia, intrauterine growth restriction and congenital malformations were not significantly affected by any treatment regimen. In included studies, aspirin did not increase the risk of bleeding, but treatment with LWMH and aspirin increased the risk of bleeding significantly in one study. Local skin reactions (pain, itching, swelling) to injection of LMWH were reported in almost 40% of patients in the same study.

AUTHORS' CONCLUSIONS

There is a limited number of studies on the efficacy and safety of aspirin and heparin in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia. Of the nine reviewed studies quality varied, different treatments were studied and of the studies at low risk of bias only one was placebo-controlled. No beneficial effect of anticoagulants in studies at low risk of bias was found. Therefore, this review does not support the use of anticoagulants in women with unexplained recurrent miscarriage. The effect of anticoagulants in women with unexplained recurrent miscarriage and inherited thrombophilia needs to be assessed in further randomised controlled trials; at present there is no evidence of a beneficial effect.

Aspirin and/or heparin for women with unexplained recurrent miscarriage with or without inherited thrombophilia

BACKGROUND

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the chance of live birth in subsequent pregnancies in women with unexplained recurrent miscarriage, with or without inherited thrombophilia.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2013) and scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on live birth in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin (UFH), and low molecular weight heparin (LMWH) for the prevention of miscarriage. One treatment could be compared with another or with no-treatment (or placebo).

DATA COLLECTION AND ANALYSIS

Two review authors (PJ and SK) assessed the studies for inclusion in the review and extracted the data. If necessary they contacted study authors for more information. We double checked the data.

MAIN RESULTS

Nine studies, including data of 1228 women, were included in the review evaluating the effect of either LMWH (enoxaparin or nadroparin in varying doses) or aspirin or a combination of both, on the chance of live birth in women with recurrent miscarriage, with or without inherited thrombophilia. Studies were heterogeneous with regard to study design and treatment regimen and three studies were considered to be at high risk of bias. Two of these three studies at high risk of bias showed a benefit of one treatment over the other, but in sensitivity analyses (in which studies at high risk of bias were excluded) anticoagulants did not have a beneficial effect on live birth, regardless of which anticoagulant was evaluated (risk ratio (RR) for live birth in women who received aspirin compared to placebo 0.94, (95% confidence interval (CI) 0.80 to 1.11, n = 256), in women who received LMWH compared to aspirin RR 1.08 (95% CI 0.93 to 1.26, n = 239), and in women who received LMWH and aspirin compared to no-treatment RR 1.01 (95% CI 0.87 to 1.16) n = 322).Obstetric complications such as preterm delivery, pre-eclampsia, intrauterine growth restriction and congenital malformations were not significantly affected by any treatment regimen. In included studies, aspirin did not increase the risk of bleeding, but treatment with LWMH and aspirin increased the risk of bleeding significantly in one study. Local skin reactions (pain, itching, swelling) to injection of LMWH were reported in almost 40% of patients in the same study.

AUTHORS' CONCLUSIONS

There is a limited number of studies on the efficacy and safety of aspirin and heparin in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia. Of the nine reviewed studies quality varied, different treatments were studied and of the studies at low risk of bias only one was placebo-controlled. No beneficial effect of anticoagulants in studies at low risk of bias was found. Therefore, this review does not support the use of anticoagulants in women with unexplained recurrent miscarriage. The effect of anticoagulants in women with unexplained recurrent miscarriage and inherited thrombophilia needs to be assessed in further randomised controlled trials; at present there is no evidence of a beneficial effect.