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

The importance of the 'uterine factor' in recurrent pregnancy loss: a retrospective cohort study on women screened through 3D transvaginal ultrasound

STUDY QUESTION

What is the prevalence of congenital and acquired anomalies of the uterus in women with recurrent pregnancy loss (RPL) of unknown etiology examined using 3D transvaginal ultrasound (US)?

SUMMARY ANSWER

Depending on the adopted diagnostic criteria, the prevalence of partial septate uterus varies between 7% and 14% and a T-shaped uterus is 3% or 4%, while adenomyosis is 23%, at least one of type 0, type 1 or type 2 myoma is 4%, and at least one endometrial polyp is 4%.

WHAT IS KNOWN ALREADY

ESHRE and the Royal College of Obstetricians and Gynaecologists guidelines on RPL recommend the adoption of the 3D transvaginal US to evaluate the 'uterine factor'. Nevertheless, there are no published studies reporting the prevalence of both congenital and acquired uterine anomalies as assessed by 3D transvaginal US and diagnosed according to the criteria proposed by the most authoritative panels of experts in a cohort of women with RPL.

STUDY DESIGN, SIZE, DURATION

This was a retrospective cohort study including 442 women with at least two previous first-trimester spontaneous pregnancy losses (i.e. non-viable intrauterine pregnancies), who referred to the obstetrics and gynecology unit of two university hospitals between July 2020 and July 2023.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Records of eligible women were reviewed. Women could be included in the study if: they were between 25 and 42 years old; they had no relevant comorbidities; they were not affected by infertility, and they had never undergone ART; they and their partner tested negative to a comprehensive RPL diagnostic work-up; and they had never undergone metroplasty, myomectomy, minimally invasive treatments for uterine fibroids or adenomyomectomy. Expert sonographers independently re-analyzed the stored 2- and 3D transvaginal US images of all included patients. Congenital uterine anomalies (CUAs) were reported according to the American Society for Reproductive Medicine (ASRM) 2021, the ESHRE/European Society for Gynaecological Endoscopy (ESGE) and the Congenital Uterine Malformation by Experts (CUME) criteria. Acquired uterine anomalies were reported according to the International Federation of Gynecology and Obstetrics (FIGO) and the Morphological Uterus Sonographic Assessment (MUSA) criteria.

MAIN RESULTS AND THE ROLE OF CHANCE

The partial septate uterus was diagnosed in 60 (14%; 95% CI: 11-17%), 29 (7%; 95% CI: 5-9%), and 47 (11%; 95% CI: 8-14%) subjects, according to the ESHRE/ESGE, the ASRM 2021, and the CUME criteria, respectively. The T-shaped uterus was diagnosed in 19 women (4%; 95% CI: 3-7%) according to the ESHRE/ESGE criteria and in 13 women (3%; 95% CI: 2-5%) according to the CUME criteria. The borderline T-shaped uterus (diagnosed when two out of three CUME criteria for T-shaped uterus were met) was observed in 16 women (4%; 95% CI: 2-6%). At least one of FIGO type 0, type 1, or type 2 myoma was detected in 4% of included subjects (95% CI: 3-6%). Adenomyosis was detected in 100 women (23%; 95% CI: 19-27%) and was significantly more prevalent in women with primary RPL and in those with three or more pregnancy losses. At least one endometrial polyp was detected in 4% of enrolled women (95% CI: 3-7%).

LIMITATIONS, REASONS FOR CAUTION

The absence of a control group prevented us from investigating the presence of an association between both congenital and acquired uterine anomalies and RPL. Second, the presence as well as the absence of both congenital and acquired uterine anomalies detected by 3D US was not confirmed by hysteroscopy. Finally, the results of the present study inevitably suffer from the intrinsic limitations of the adopted classification systems.

WIDER IMPLICATIONS OF THE FINDINGS

The prevalence of CUAs in women with RPL varies depending on the classification system used. For reasons of clarity, the US reports should always state the name of the uterine anomaly as well as the adopted classification and diagnostic criteria. Adenomyosis seems to be associated with more severe forms of RPL. The prevalence rates estimated by our study as well as the replicability of the adopted diagnostic criteria provide a basis for the design and sample size calculation of prospective studies.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was used. The authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Evaluation of Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) affects approximately 5% of couples. Although RPL definitions vary across professional societies, an evaluation after a second clinically recognized first-trimester pregnancy loss is recommended. Good quality evidence links parental chromosomal rearrangements, uterine anomalies, and antiphospholipid syndrome (APS) to RPL. In contrast, the relationship between RPL and other endocrine, hematologic, and immunologic disorders or environmental exposures is less clear. Anticoagulant therapy and low-dose aspirin are recommended for patients with RPL who have also been diagnosed with APS. Vaginal progesterone supplementation may be considered in patients experiencing vaginal bleeding during the first trimester. Surgical correction may be considered for patients with RPL in whom a uterine anomaly is identified. Evaluation and management of additional comorbidities should be guided by the patient's history rather than solely based on the diagnosis of RPL, with the goal of improving overall health to reduce complications in the event of pregnancy. Most people with RPL, including those without identifiable risk factors, are expected to achieve a live birth within 5 years from the initial evaluation. Nevertheless, clinicians should be sensitive to the psychological needs of individuals with this condition and provide compassionate and supportive care across all stages.

Effects of NGS-based PGT-a for idiopathic recurrent pregnancy loss and implantation failure: a retrospective cohort study

To clarify the effect of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidy (PGT-A) combined with trophectoderm (TE) biopsy on the pregnancy outcomes of idiopathic recurrent pregnancy loss (iRPL) and idiopathic recurrent implantation failure (iRIF), we conducted a retrospective cohort study of 212 iRPL couples and 66 iRIF couples who underwent PGT-A or conventional in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment. The implantation rate (IR) per transfer (64.2%), clinical pregnancy rate (CPR) per transfer (57.5%), and live birth rate (LBR) per transfer (45%) of iRPL couples of the PGT-A treatment group were significantly higher (p < 0.05) than those of the conventional IVF/ICSI group (IR per transfer,38.2%; CPR per transfer,33.3%; LBR per transfer, 28.4%), whereas the pregnancy loss rate (PLR) per transfer was similar between the two groups. These effects were also significant (p < 0.05) in iRPL couples with advanced maternal age (AMA, ≥35 years), whereas no significant differences were found in clinical outcomes between the PGT-A and conventional IVF/ICSI groups in younger iRPL couples (<35 years). The cumulative clinical outcomes of iRPL couples were comparable between the PGT-A and conventional IVF/ICSI groups. No significant differences were found in any clinical outcomes between the PGT-A and conventional IVF/ICSI groups for young or AMA couples with iRIF. In conclusion, NGS-based PGT-A involving TE biopsy may be useful for iRPL women to shorten the time to pregnancy and reduce their physical and psychological burden, especially for iRPL women with AMA; however, couples with iRIF may not benefit from PGT-A treatment. Considering the small sample size of the iRIF group, further investigations with a larger sample size are needed to verify our findings.

Microenvironment of the Lower Reproductive Tract: Focus on the Cervical Mucus Plug

The female lower reproductive tract microbiota is a complex ecosystem comprising various microorganisms that play a pivotal role in maintaining women's reproductive well-being. During pregnancy, the vaginal microbiota undergoes dynamic changes that are important for a successful gestation. This review summarizes the implications of the cervical mucus plug microenvironment and its profound impact on reproductive health. Further, the symbiotic relationship between the vaginal microbiome and the cervical mucus plug is highlighted, with a special emphasis on how this natural barrier serves as a guardian against ascending infections. Understanding this complex host-microbes interplay could pave the way for innovative approaches to improve women's reproductive health and fertility.

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.

The Mac Is Back: The Role of Macrophages in Human Healthy and Complicated Pregnancies

Pregnancy is a fascinating immunological paradox: the semi-allogeneic fetus generally grows without any complications. In the placenta, fetal trophoblast cells come into contact with maternal immune cells. Inaccurate or inadequate adaptations of the maternal immune system could lead to problems with the functioning of the placenta. Macrophages are important for tissue homeostasis, cleanup, and the repair of damaged tissues. This is crucial for a rapidly developing organ such as the placenta. The consensus on macrophages at the maternal-fetal interface in pregnancy is that a major proportion have an anti-inflammatory, M2-like phenotype, that expresses scavenger receptors and is involved in tissue remodeling and the dampening of the immune reactions. Recent multidimensional analyses have contributed to a more detailed outlook on macrophages. The new view is that this lineage represents a highly diverse phenotype and is more prevalent than previously thought. Spatial-temporal in situ analyses during gestation have identified unique interactions of macrophages both with trophoblasts and with T cells at different trimesters of pregnancy. Here, we elaborate on the role of macrophages during early human pregnancy and at later gestation. Their possible effect is reviewed in the context of HLA incompatibility between mother and fetus, first in naturally conceived pregnancies, but foremost in pregnancies after oocyte donation. The potential functional consequences of macrophages for pregnancy-related immune reactions and the outcome in patients with recurrent pregnancy loss are also discussed.

Prevalence and associated factors of recurrent pregnancy loss in Nigeria according to different national and international criteria (ASRM/ESHRE vs. WHO/RCOG)

Background

In low-and middle-income countries, no conclusive research explains the prevalence and associated factors of women with a history of recurrent pregnancy loss (RPL). Some authorities have recommended further scientific research on the effect of various definitions of RPL.

Objective

To assess prevalence and associated factors of RPL among pregnant women in Nigeria according to different national and international criteria: the American Society for Reproductive Medicine/ European Society for Human Reproduction and Embryology (ASRM/ESHRE; two losses) and the World Health Organization/ Royal College of Obstetricians and Gynecologists (WHO/RCOG; three consecutive losses) criteria.

Methods

This is a cross-sectional analytical study wherein, pregnant women with prior RPL were investigated. The outcome measures were prevalence and risk factors. The associations between independent variables and outcome variable were explored using bivariate and multivariable logistic regression models. The results of these analyses were reported as adjusted odds ratios (AORs) with 95% confidence intervals (95%CI). Factors associated with RPL were identified using multivariate regression models.

Result

Of the 378 pregnant women interviewed, the overall prevalence of RPL in this study was found to be 15.34% (95% confidence interval = 11.65%-19.84%). The prevalence of RPL was 15.34% (58/378; 95%CI = 11.65%-19.84%) and 5.29% (20/378; 95%CI = 3.23%-8.17) according to the ASRM and the WHO criterion respectively. Regardless of diagnostic criteria, unexplained (AOR = 23.04; 95%CI: 11.46-36.32), endocrine disturbances (AOR = 9.76; 95%CI: 1.61-63.19), uterine abnormalities (AOR = 13.57; 95%CI: 3.54-50.60), and antiphospholipid syndrome (AOR = 24.59; 95%CI: 8.45-71.04) were positively and independently associated with RPL. No significant risk factors were seen when the ASRM/ ESHRE criterion vs. WHO/RCOG criterion were compared. Advanced maternal age was significantly higher in secondary than in primary type of RPL.

Conclusion

The prevalence of RPL was 15.34% and 5.29% according to ASRM/ESHRE and WHO/RCOG criterion respectively, with secondary type predominating. No significant differences with regard to risk factors were seen according to diagnostic criteria studied, though advanced maternal age was significantly higher in secondary RPL. Further research is needed to confirm our findings and to better characterize the magnitude of differences.

Does a history of recurrent pregnancy loss affect subsequent obstetric outcomes and placental findings in in vitro fertilization?

PURPOSE

To assess perinatal outcomes and placental findings in in vitro fertilization (IVF) patients with previous recurrent pregnancy loss (RPL).

METHODS

This was a retrospective cohort of live singleton births following IVF at a single university-affiliated center between 2009 and 2017. Outcomes were compared between patients with previous RPL, defined as two miscarriages (RPL group), and patients without RPL (control group). Placental examination was performed for all deliveries irrelevant of complications, and findings categorized according to the Amsterdam Placental Workshop Consensus.

RESULTS

One hundred seventy-two deliveries of women with previous RPL (RPL group) were compared to 885 controls. Maternal age, 36.2 ± 4.2 vs. 35.4 ± 4.2 years, p = 0.02, and rate of uterine fibroids, 12.7% vs. 7.3%, p = 0.01, were higher in the RPL group. The rate of nulliparity was lower in the RPL group, 63.3% vs. 74.1%, p = 0.003. Unexplained infertility and diminished ovarian reserve were more common in the RPL group and male factor infertility in controls. There was a lower rate of fresh embryo transfer in the RPL group, 50.5% vs. 64.7%, p < 0.001, and reduced endometrial thickness. Similar obstetric outcomes were noted in the groups after adjustment for confounders. Placental examinations were notable for lower placental thickness, β - 0.17 cm, 95%CI - 0.30-(- 0.0), a lower rate of velamentous cord insertion, aOR 0.44, 95%CI 0.20-0.95, and a higher rate of villous infarction, aOR 2.82, 95%CI 1.28-6.20 in the RPL group.

CONCLUSION

In IVF patients with a history of RPL, subsequent deliveries were associated with a limited number of placental lesions, yet with similar obstetric outcomes.

How we define recurrent miscarriage matters: A qualitative exploration of the views of people with professional or lived experience

BACKGROUND

Recurrent miscarriage (RM) affects 1%-3% of women/couples of reproductive age depending on the definition used, for example, whether 2 or ≥3 miscarriages. Stakeholders' views of how RM is defined have received limited attention to date. A definition reflects the medical evidence and values of a society at the time, and thus warrants ongoing review.

AIM

We aimed to explore the views of couples are offered and men with lived experience of RM, and those involved in the delivery/management of services and supports, on how RM is and/or should be defined.

METHODS

We adopted a qualitative study design, incorporating semi-structured interviews. We used purposive sampling to recruit participants in the Republic of Ireland, ensuring diverse perspectives were included. Women and men with lived experience of ≥2 consecutive first-trimester miscarriages were recruited via health professionals and social media; other participants via the research team's networks. Interviews were audio-recorded, transcribed, pseudo-anonymized and analysed using reflexive thematic analysis.

FINDINGS

We conducted interviews with 42 health professionals/service providers and 13 couples are offered and 7 men with lived experience of RM (June 2020 to February 2021). We generated three interrelated themes from the data: (i) The need for a standardized definition of recurrent miscarriage-Finding a balance between research evidence, individual needs and healthcare resources, (ii) The definition is a route to finding an answer and/or validating women/couples' experience of loss and (iii) Working around the definition-Advocacy and impacts.

CONCLUSION

A nuanced approach to defining RM is warranted, one which is evidence-informed recognizes the individual needs of women/couples, and considers healthcare resources.

PATIENT OR PUBLIC CONTRIBUTION

Members of the multidisciplinary RE:CURRENT (REcurrent miscarriage: evaluating CURRENT services) Project Research Advisory Group (including four parent advocates, two of whom are co-authors on this article) were actively involved throughout the study, including the generation of topic guides and the refining of themes.

Development of the OPAL prediction model for prediction of live birth in couples with recurrent pregnancy loss: protocol for a prospective and retrospective cohort study in the Netherlands

INTRODUCTION

Recurrent pregnancy loss (RPL) is defined as the loss of two or more conceptions before 24 weeks gestation. Despite extensive diagnostic workup, in only 25%-40% an underlying cause is identified. Several factors may increase the risk for miscarriage, but the chance of a successful pregnancy is still high. Prognostic counselling plays a significant role in supportive care. The main limitation in current prediction models is the lack of a sufficiently large cohort, adjustment for relevant risk factors, and separation between cumulative live birth rate and the success chance in the next conception. In this project, we aim to make an individualised prognosis for the future chance of pregnancy success, which could lead to improved well-being and the ability managing reproductive choices.

METHODS AND ANALYSIS

In this multicentre study, we will include both a prospective and a retrospective cohort of at least 931 and 1000 couples with RPL, respectively. Couples who have visited one of the three participating university hospitals in the Netherlands for intake are eligible for the study participation, with a follow-up duration of 5 years. General medical and obstetric history and reports of pregnancies after the initial consultation will be collected. Multiple imputation will be performed to cope for missing data. A Cox proportional hazards model for time to pregnancy will be developed to estimate the cumulative chance of a live birth within 3 years after intake. To dynamically estimate the chance of an ongoing pregnancy, given the outcome of earlier pregnancies after intake, a logistic regression model will be developed.

ETHICS AND DISSEMINATION

The Medical Ethical Research Committee of the Leiden University Medical Center approved this study protocol (N22.025). There are no risks or burden associated with this study. Participant written informed consent is required for both cohorts. Findings will be published in peer-reviewed journals and presentations at international conferences.

TRIAL REGISTRATION NUMBER

NCT05167812.

Soluble HLA-G blood levels are not increased during ongoing pregnancy in women with a history of recurrent pregnancy loss

Recurrent pregnancy loss (RPL) affects 1-2 % of couples who are trying to conceive. At some point, some couples do maintain a healthy pregnancy to term, but the underlying mechanism of RPL remains elusive. Human leukocyte antigen (HLA)-G is an immune modulatory molecule. Our group previously showed increased HLA-G levels in the decidua of term pregnancies after RPL, while other studies showed reduced soluble HLA-G (sHLA-G) blood levels in women with RPL. This led us to investigate sHLA-G levels in blood of women with RPL who had either a subsequent pregnancy loss (RPL-pregnancy loss) or a healthy term pregnancy (RPL-live birth), and compare these to healthy control pregnancies and non-pregnant controls. Soluble HLA-G concentrations were quantified by ELISA. Women with healthy term pregnancy had increased sHLA-G levels compared to non-pregnant controls. In contrast, RPL-live birth women at term did not have increased blood sHLA-G levels. Soluble HLA-G levels remained stable between first and third trimester. Interestingly, when comparing first trimester samples of RPL-live birth to RPL-pregnancy loss, sHLA-G levels also did not significantly differ. High sHLA-G levels in blood seem not to be crucial for an ongoing healthy pregnancy after RPL. However, since it was previously shown that women with RPL-live birth have increased HLA-G levels in term decidua compared to control pregnancies, the current data suggest that local and systemic immune regulation are not necessarily in concert. Further study of the contribution of fetus-derived HLA-G and HLA-G of maternal origin may provide more insight in the pathophysiology of RPL.

Reproductive Failure and Thrombophilia: Not Enough Evidence for a Tight Bond

OBJECTIVES

The role of hereditary thrombophilia in reproductive failure (RF) is strongly debatable. In this retrospective single-center study, we analyzed pregnancy outcome in 175 women screened for thrombophilia after at least one event of RF.

RESULTS

The prevalence of thrombophilia in our cohort was 33.4%. Pregnancy survival curves were not different according to severity (log-rank, p = 0.302) or type of thrombophilia (log-rank, p = 0.532). In total, 81.7% of 175 subsequent pregnancies were proceeded with LMWH. Concomitant use of ASA was prescribed in 75 pregnancies according to physician choice. The primary endpoint was live birth rate (LBR) that succeeded in 152/175 next pregnancies (86.8%) and late obstetric complications (LOBC) which occurred in 17/175 next pregnancies (9.8%). In logistic regression analysis, neither the severity nor the type of thrombophilia was important for any pregnancy outcome (LBR or LOBC). Considering therapeutic interventions, the use of LMWH ± ASA was not related to LBR or LOBC. The only factor inversely related to LBR was age above the cutoff value of 35.5 years (p = 0.049).

CONCLUSIONS

Incidence of thrombophilia is increased among women with RF, but the severity or type of thrombophilia is not related to pregnancy outcome.

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.

Extensive serum biomarker analysis in the prethrombotic state of recurrent spontaneous abortion

The prethrombotic state (PTS) is a possible cause of recurrent spontaneous abortion (RSA). The aim of this study was to identify serum biomarkers for the detection of RSA with PTS (PSRSA). A Quantibody array 440 was used to screen novel serum‐based biomarkers for PSRSA/NRSA (RSA without PTS). Proteins differentially expressed in PSRSA were analysed using bioinformatics methods and subjected to a customized array and enzyme‐linked immunosorbent assay (ELISA) validation. We used receiver operating characteristic to calculate diagnostic accuracy, and machine learning methods to establish a biomarker model for evaluation of the identified targets. 20 targets were selected for validation using a customized array, and seven targets via ELISA. The decision tree model showed that IL‐24 was the first node and eotaxin‐3 was the second node distinguishing the PSRSA and NRSA groups (an accuracy rate of 100% and an AUC of 1). Epidermal growth factor (EGF) as the node distinguished the PSRSA and NC groups (an accuracy rate of 100% and an AUC of 1). EGF as the node distinguished the NRSA and NC groups (an accuracy rate of 96.5% and an AUC of 0.998). Serum DNAM‐1, BAFF, CNTF, LAG‐3, IL‐24, Eotaxin‐3 and EGF represent a panel of promising diagnostic biomarkers to detect the PSRSA.

Genetic testing of products of conception in recurrent pregnancy loss evaluation

Genetic testing of products of conception (POC) has been proposed as a tool to be used in the evaluation of patients with recurrent pregnancy loss (RPL). Following a complete RPL evaluation, POC results may reveal an aneuploidy and provide an explanation for the miscarriage in more than 55% of cases. When the cytogenetic result of the pregnancy loss reveals a euploid pregnancy, management should be directed towards the identification of treatable abnormalities. Furthermore, the results of POC testing might better define a subgroup of patients with unexplained RPL who may benefit from expectant management versus preimplantation genetics (aneuploid unexplained RPL) or investigational therapy (euploid unexplained RPL).

Telomere Length in Idiopathic Recurrent Pregnancy Loss

OBJECTIVE

Telomere length is used as an indicator of biological aging. It is well known that one of the most remarkable risk factors of recurrent pregnancy losses is advanced maternal age. The objective of this study was to investigate the correlation between idiopathic recurrent pregnancy loss and telomere length.

METHOD

The study group included 40 women, while the control group consisted of 41 healthy women whose age and body mass index were matched. A venous blood sample was taken from all participants into EDTA tubes in the early follicular phase, and telomere length was measured through the qPCR technique.

RESULTS

When the mean TL of the groups was compared, it was determined that TL was significantly shorter among the iRPL group (7763.89±924.58 base pair) compared to the control group (8398.84±1102.95 base pair) (p<0.006). Whereas FSH and E2 were higher in the iRPL group, TAFC was lower (p<0.001). When the correlation between telomere length and endocrine parameters was statistically tested in the iRPL group, a negative correlation was found between FSH and telomere length (r=-0.437; p<0.001).

CONCLUSION

Shortened telomere length might play a role in the etiology of iRPL. We are of the opinion that patients with RPL should be screened for the presence of cardiovascular diseases and other chronic diseases, as is the case for POF.