Whole exome sequencing identifies a novel mutation in Annexin A4 that is associated with recurrent spontaneous abortion

Background

Recurrent spontaneous abortion (RSA) is a multifactorial disease, the exact causes of which are still unknown. Environmental, maternal, and genetic factors have been shown to contribute to this condition. The aim of this study was to investigate the presence of mutations in the ANXA4 gene in patients with RSA.

Methods

Genomic DNA was extracted from 325 patients with RSA and 941 control women with a normal reproductive history for whole-exome sequencing (WES). The detected variants were annotated and filtered, and the pathogenicity of the variants was predicted through the SIFT online tool, functional enrichment analyses, Sanger sequencing validation, prediction of changes in protein structure, and evolutionary conservation analysis. Furthermore, plasmid construction, Western blotting, RT-qPCR, and cell migration, invasion and adhesion assays were used to detect the effects of ANXA4 mutations on protein function.

Results

An ANXA4 mutation (p.G8D) in 1 of the 325 samples from patients with RSA (RSA-219) was identified through WES. This mutation was not detected in 941 controls or included in public databases. Evolutionary conservation analysis revealed that the amino acid residue affected by the mutation (p.G8D) was highly conserved among 13 vertebrate species, and the SIFT program and structural modeling analysis predicted that this mutation was harmful. Furthermore, functional assays revealed that this mutation could inhibit cell migration, invasion and adhesion.

Conclusion

Our study suggests that an unreported novel ANXA4 mutation (p.G8D) plays an important role in the pathogenesis of RSA and may contribute to the genetic diagnosis of RSA.

Social consequences of recurrent pregnancy loss and maternal myths, past, present, and future in Japan

In Japan, the myth of motherhood, the idea that every woman harbours maternal love and that a woman only becomes a full-fledged woman after giving birth, has existed for a long time. However, there has been a limited number of studies concerning this motherhood myth in patients with recurrent pregnancy loss (RPL). The present study aimed to examine the experiences of maternal myths in patients with RPL and to determine whether maternal myths affect depression. Participants in the study included 61 patients in 1995, 71 patients in 2002, 503 patients from 2008 to 2012, and 318 patients and 1210 pregnant women from 2017 to 2020. Patients who sought an examination of their RPL visited Nagoya City University Hospital, while pregnant women requiring a prenatal checkup visited Nagoya City West Medical Center. Both groups completed a questionnaire concerning seven maternal myths and how they rated their level of depression (K6). It was found that not only patients with RPL but also pregnant women with no pregnancy loss had encountered maternal myths and many of them felt some discomfort. It has become clear that exposure to such myths has decreased over the 25 years from 1995 to 2020 (p < 0.05). Additionally, opportunities for exposure to maternal myths clearly had an impact on depression (p < 0.05). It is imperative that we recognize the distress caused by these myths. One potential solution to this problem is to improve education on gender issues.

Preimplantation genetic testing for aneuploidy in unexplained recurrent pregnancy loss: a systematic review and meta-analysis

IMPORTANCE

Preimplantation genetic testing for aneuploidy (PGT-A) to deselect aneuploid embryos in assisted reproductive technology (ART) treatment cycles may hold promise by augmenting pregnancy rates per transfer and reducing pregnancy loss rates for patients with unexplained recurrent pregnancy loss (RPL).

OBJECTIVE

To explore effectiveness of PGT-A in managing unexplained RPL by evaluating several key aspects: the likelihood of live birth in a subsequent spontaneous pregnancy, whether women with unexplained RPL have a higher rate of aneuploidy, whether euploid blastocysts offer comparable live birth rate (LBR) in patients with unexplained RPL, whether the endometrium is less selective in unexplained RPL loss, and whether PGT-A increases the LBR or reduces pregnancy losses until delivery.

DATA SOURCES

PubMed and Cochrane Library databases were searched from inception until June 2024.

STUDY SELECTION AND SYNTHESIS

Studies involving patients with ≥2 unexplained RPL who underwent ART with or without PGT-A or expectant management were included.

MAIN OUTCOME MEASURES

The primary outcome measure was the LBR. Secondary outcome measures were aneuploidy rate, clinical pregnancy rate, and clinical pregnancy loss rate.

RESULTS

Whether couples with unexplained RPL have higher embryo aneuploidy rates remains equivocal. Euploid blastocyst transfers yielded comparable clinical pregnancy loss rate (odds ratio [OR], 1.10; 95% confidence interval [CI], 0.57-2.13) and LBR (OR, 1.04; 95% CI, 0.74-1.44) in patients with and without unexplained RPL. Comprehensive chromosome analysis of products of conception shows similar aneuploidy rates between patients with and without RPL and does not support the less selective endometrium hypothesis. Preimplantation genetic testing for aneuploidy decreased clinical pregnancy loss rate (OR, 0.42; 95% CI, 0.27-0.67) and enhanced LBR per transfer (OR, 2.17; 95% CI, 1.77-2.65) and LBR per patient (OR, 1.85; 95% CI, 1.18-2.91) in patients with unexplained RPL.

CONCLUSION AND RELEVANCE

Current low-quality evidence suggests that PGT-A enhances LBR per transfer and per patient in unexplained RPL. Well-designed randomized controlled trials comparing ART with PGT-A vs. expectant management for unexplained RPL are warranted.

CLINICAL TRIAL REGISTRATION NUMBER

CRD42021291546.

Cell-Free DNA Analysis of Fetal Aneuploidies in Early Pregnancy Loss

Background: Products of conception samples are often collected and analyzed to try to determine the cause of an early pregnancy loss. However, sample collection may not always be possible, and maternal cell contamination and culture failure can affect the analysis. Cell-free DNA-based analysis of a blood sample could be used as an alternative method in early pregnancy loss cases to detect if aneuploidies were present in the fetus. Methods: In this prospective study, blood samples from early pregnancy loss patients were analyzed for the presence of fetal aneuploidies using a modified version of a noninvasive prenatal testing assay for cell-free DNA analysis. Results from cell-free DNA analysis were compared against the gold standard, microarray analysis of products of conception samples. This study was registered with ClinicalTrials.gov, identifier: NCT04935138. Results: Of the 76 patient samples included in the final study cohort, 11 were excluded from performance calculations. The 65 patient samples included in the final analysis included 49 with an abnormal microarray result and 16 with a normal microarray result. Based on results from these 65 samples, the study found that genome-wide cell-free DNA analysis had a sensitivity of 73.5% with a specificity of 100% for the detection of fetal aneuploidies in early pregnancy loss cases. Conclusions: This prospective study provides further support for the utility of cell-free DNA analysis in detecting fetal aneuploidies in early pregnancy loss cases. This approach could allow for a noninvasive method of investigating the etiology of miscarriages to be made available clinically.

Role of genetic analysis of products of conception and PGT in managing early pregnancy loss

This article considers the addition of comprehensive 24-chromosomal microarray (CMA) analysis of products of conception (POC) to a standard evaluation for recurrent pregnancy loss (RPL) to help direct treatment towards expectant management versus IVF with preimplantation genetic testing for aneuploidies (PGT-A). The review included retrospective data from 65,333 miscarriages, a prospective evaluation of 378 couples with RPL who had CMA testing of POC and the standard workup, and data from an additional 1020 couples who were evaluated for RPL but did not undergo CMA testing of POC. Aneuploidy in POC explained the pregnancy loss in 57.7% (218/378) of cases. In contrast, the full RPL evaluation recommended by the American Society for Reproductive Medicine identified a potential cause in only 42.9% (600/1398). Combining the data from the RPL evaluation and the results of genetic testing of POC provides a probable explanation for the loss in over 90% (347/378) of women. Couples with an unexplained loss after the standard evaluation with POC aneuploidy accounted for 41% of cases; PGT-A may be considered after expectant management. Conversely, PGT-A would have a limited role in those with a euploid loss and a possible explanation after the standard workup. Categorizing a pregnancy loss as an explained versus unexplained loss after the standard evaluation combined with the results of CMA testing of POC may help identify patients who would benefit from expectant management versus PGT-A.

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.

Mechanisms of YAP1-mediated trophoblast ferroptosis in recurrent pregnancy loss

PURPOSE

The purpose of our study is to investigate the function of YAP1 in the trophoblast ferroptosis and maternal-fetal interface communication of RPL.

METHODS

We collected 25 villous tissues and detected the expression of YAP1. Cell counting kit-8 assay, scratch wound-healing assay, and Matrigel invasion assay were performed to observe the proliferation, migration, and invasion of HTR-8/SVneo and JAR cells. Subsequently, measured the levels of reactive oxygen species (ROS), malondialdehyde (MDA), reduced glutathione (GSH), SLC7A11, SOD2, and GPX4. Ultimately, the use of ferroptosis activator (erastin) and inhibitor (Ferrostatin-1, fer-1) further confirmed the regulation by YAP1. In addition, established an in vitro-induced cell model to study the effect of YAP1 on the decidualization process. Finally, animal models were implemented for further confirmation.

RESULTS

We found that YAP1 was downregulated in RPL patients. Overexpression of YAP1 could significantly enhance the proliferation, migration, and invasion of trophoblasts, and inhibit ferroptosis. Knocking down YAP1 exhibited the opposite effect. Rescue experiments have shown that YAP1 could upregulate the expression of SLC7A11 and GPX4, which are key molecules in the classic pathway of ferroptosis. In addition, the decidualization was impaired when hESCs were treated with conditioned medium of YAP1 knockdown trophoblasts. Moreover, we found that Yap1, Slc7a11, and Gpx4 were downregulated in the RPL mice, along with increased MDA and decreased GSH.

CONCLUSION

Downregulation of YAP1 induces ferroptosis, thereby damaging the trophoblast invasion processes, which also disturbs the communication at the maternal-fetal interface. Our study identified YAP1 as a potential key molecule in the pathogenesis of RPL.

Maternal-fetal immunity and recurrent spontaneous abortion

Recurrent Spontaneous Abortion (RSA) is a common pregnancy complication, that has multifactorial causes, and currently, 40%-50% of cases remain unexplained, referred to as Unexplained RSA (URSA). Due to the elusive etiology and mechanisms, clinical management is exceedingly challenging. In recent years, with the progress in reproductive immunology, a growing body of evidence suggests a relationship between URSA and maternal-fetal immunology, offering hope for the development of tailored treatment strategies. This article provides an immunological perspective on the pathogenesis, diagnosis, and treatment of RSA. On one hand, it comprehensively reviews the immunological mechanisms underlying RSA, including abnormalities in maternal-fetal interface immune tolerance, maternal-fetal interface immune cell function, gut microbiota-mediated immune dysregulation, and vaginal microbiota-mediated immune anomalies. On the other hand, it presents the diagnosis and existing treatment modalities for RSA. This article offers a clear knowledge framework for understanding RSA from an immunological standpoint. In conclusion, while the "layers of the veil" regarding immunological factors in RSA are gradually being unveiled, our current research may only scratch the surface. In terms of immunological etiology, effective diagnostic tools for RSA are currently lacking, and the efficacy and safety of immunotherapies, primarily based on lymphocyte immunotherapy and intravenous immunoglobulin, remain contentious.

Baicalin ameliorates deficient decidualization in URSA by regulating mitochondrial fission induced necroptosis

Unexplained recurrent spontaneous abortion (URSA) is a common complication of pregnancy that affects the health of pregnant women. Deficient endometrial decidualization has been associated with URSA. However, the underlying mechanism is poorly understood. This study aims to explore the mechanisms of mitochondrial fission induced necroptosis in deficient decidualization in URSA, and explore the regulation of baicalin on this mechanism. Initially, decidual tissues were collected from patients with URSA and health controls. Subsequently, in vitro induced decidualization model of Telomerase-Immortalized Human Endometrial Stromal Cells (T-hESCs) was constructed. Additionally, murine models of URSA (CBA/J × DBA/2) and normal pregnancy (CBA/J × BALB/c) were established, respectively. The level of decidualization, necroptosis, and mitochondrial fission of decidual tissues from clinical samples were detected. The function of mitochondrial fission on necroptosis during decidualization in T-hESCs was assessed by enhancing or inhibiting mitochondrial fission or necroptosis. Finally, CBA/J × DBA/2 pregnant mice were administrated with different doses of baicalin or saline, and the expression of mitochondrial fission, necroptosis, and decidualization markers were verified. The results of the study demonstrated a significant decrease in decidualization markers in the decidual tissues of URSA patients (P < 0.05), along with an increase in the incidence of cell necroptosis (P < 0.05) and hyperactive mitochondrial fission (P < 0.05). In vitro experiments, LPS was induced to trigger necroptosis of T-hESCs during induced decidualization, and decidualization markers IGFBP1 and PRL were subsequently decreased (P < 0.05). Besides, the mitochondrial fission agonist Tyrphostin A9 was found to promote the level of necroptosis (P < 0.05) and induced deficient decidualization (P < 0.05), which could be rescued by mitochondrial fission inhibitor Mdivi-1 and necroptosis inhibitor Nec-1 (P < 0.05). In addition, baicalin was shown to reduce hyperactive mitochondrial fission (P < 0.05), necroptosis (P < 0.05) and ameliorate deficient decidualization in vitro and in URSA murine models (P < 0.05). Collectively, baicalin shows potential in ameliorating deficient decidualization in URSA by inhibiting mitochondrial fission-triggered necroptosis.

Expanding the role of chromosomal microarray analysis in the evaluation of recurrent pregnancy loss

Multiple factors contribute to recurrent pregnancy loss (RPL). This review highlights the latest international guidelines for RPL workup, including immunological testing, by the American Society for Reproductive Medicine (ASRM), the European Society of Human Reproduction and Embryology (ESHRE), and the Royal College of Obstetricians and Gynaecologists (RCOG). These three societies recommend testing for antiphospholipid syndrome. ESHRE and RCOG also recommend thyroid peroxidase antibody testing, whereas ASRM does not. All guidelines advise against testing of natural killer cells, cytokines, antinuclear antibodies, human leukocyte antigen (HLA) compatibility, anti-HLA antibodies, and anti-sperm antibodies. However, when following ASRM, ESHRE or RCOG diagnostic guidelines, over 50% of cases have no identifiable cause. Genetic testing of products of conception (POC) can improve our understanding of unexplained RPL as aneuploidy is a common cause of RPL. Based on studies reporting results from chromosomal microarray analysis (CMA) of POC, we propose a novel algorithm for RPL evaluation. The algorithm involves following evidence-based societal guidelines (published by ASRM, ESHRE, or RCOG), excluding parental karyotyping, in combination with CMA testing of miscarriage tissue. When utilizing this new evaluation algorithm, the number of unexplained cases of RPL decreases from over 50% to less than 10%. As a result, most patients are provided an explanation for their loss and healthcare costs are potentially reduced. Patients with an otherwise negative workup with euploid POC, are classified as "truly unexplained RPL". These patients are excellent candidates for enrollment in randomized, controlled trials examining novel immunological testing and treatment protocols.

Non-invasive cell-free DNA-based approach for the diagnosis of clinical miscarriage: A retrospective study

OBJECTIVE

To evaluate cell-free DNA (cfDNA) testing as a non-invasive approach to detecting aneuploidies in clinical miscarriages.

DESIGN

A retrospective cohort study of women with pregnancy loss.

SETTING

Hospitals and genetic analysis laboratories.

POPULATION OR SAMPLE

Pregnancy losses in the period 2021-2022.

METHODS

Results derived from non-invasive cfDNA testing (Veriseq NIPT Solution V2) of maternal blood and invasive analysis of products of conception (POC) (Ion ReproSeq) compared in 120 women who suffered a miscarriage.

MAIN OUTCOME MEASURES

Concordance rate results, cfDNA testing performance, non-informative rate (NIR) and fetal fraction (FF).

RESULTS

We found no significant differences in the NIR between invasive (iPOC) and non-invasive (niPOC) analysis of POC (10.0% [12/120] versus 16.7% [20/120]). Of 120 samples, 90 provided an informative result in iPOC and niPOC groups (75%). cfDNA analysis correctly identified 74/87 (85.1%) samples (excluding triploidies). Sensitivity and specificity were 79.4% and 100%, respectively; all discordant cases were female. A binomial logistic model suggested fetal sex as the only variable influencing the concordance rate (P = 0.035). A Y-chromosome-based FF estimate allowed the optimal reclassification of cfDNA of non-informative male fetuses and a more accurate evaluation of cfDNA testing performance. The difference between the two FF estimates (native algorithm and Y-chromosome-based) suggests that female non-concordant cases may represent non-informative cases.

CONCLUSIONS

Cell-free DNA-based testing provides a non-invasive approach to determining the genetic cause of clinical miscarriage.

Differential expression of immune checkpoints (OX40/OX40L and PD-1/PD-L1) in decidua of unexplained recurrent spontaneous abortion women

In this study, we aimed to investigate the expression of OX40, OX40L, PD-1 and PD-L1 in patients with unexplained recurrent spontaneous abortion (URSA) compared to normal pregnancies (NP). A total of 50 patients who were diagnosed with URSA and 41 NP were recruited to this study. Real-time polymerase chain reaction (RT-PCR) was used to determine the expression of OX40, OX40L, PD-1 and PD-L1 in decidual tissues; Immunohistochemistry (IHC) was conducted to characterize the distribution of the involved genes in decidual tissues; Double immunofluorescence staining was used to prove the localization of the involved genes in decidual tissues. The concentrations of OX40L and PD-L1 in plasma were measured with enzyme-linked immunosorbent assay (ELISA). The expression of OX40L in the decidua of URSA patients was significantly increased compared to that in the NP group, while the expression of PD-L1 in the URSA group was decreased compared to that in the NP group. Both proteins are localized in the decidual stroma as analyzed by double immunofluorescence staining. The staining results were confirmed at the mRNA level of decidual tissues, while the mRNA level of peripheral blood showed no significant difference. In conclusion, the results suggest that decidual stromal cells may promote the interaction with OX40 on T cells by upregulating the expression of OX40L and reduce the interaction with PD-1 on T cells by downregulating the expression of PD-L1 in URSA patients, which may interfere with the immune tolerance of the maternal-fetal interface, leading to poor pregnancy outcomes.

Current Applications and Controversies in Preimplantation Genetic Testing for Aneuploidies (PGT-A) in In Vitro Fertilization

Preimplantation genetic testing for aneuploidy (PGT-A) has evolved over recent years, including improvements in embryo culture, biopsy, transfer, and genetic testing. The application of new comprehensive chromosome screening analysis has improved the accuracy in determining the chromosomal status of the analyzed sample, but it has brought new challenges such as the management of partial aneuploidies and mosaicisms. For the past two decades, PGT-A has been involved in a controversy regarding its efficiency in improving IVF outcomes, despite its widespread worldwide implementation. Understanding the impact of embryo aneuploidy in IVF (in vitro fertilization) should theoretically allow improving reproductive outcomes. This review of the literature aims to describe the impact of aneuploidy in human reproduction and how PGT-A was introduced to overcome this obstacle in IVF (in vitro fertilization). The article will try to analyze and summarize the evolution of the PGT-A in the recent years, and its current applications and limitations, as well as the controversy it generates. Conflicting published data could indicate the lacking value of a single biopsied sample to determine embryo chromosomal status and/or the lack of standardized methods for embryo culture and management and genetic analysis among other factors. It has to be considered that PGT-A may not be a universal test to improve the reproductive potential in IVF patients, rather each clinic should evaluate the efficacy of PGT-A in their IVF program based on their population, skills, and limitations.

Lived experience of recurrent miscarriage: women and their partners' experience of subsequent pregnancy and support within an NHS specialist clinic - a qualitative study

OBJECTIVE

This study aims to describe the lived experiences of couples with a history of recurrent miscarriage in subsequent pregnancies and their perception of clinic support and cytogenetic investigations.

DESIGN

A qualitative interview study with a phenomenological approach. Semistructured interviews were conducted using video conferencing software. Two researchers coded the transcripts and developed themes.

SETTING

A National Health Service (NHS) hospital in central England between May 2021 and July 2021, during the COVID-19 pandemic.

PARTICIPANTS

Patients attending a specialist recurrent miscarriage clinic and their partners. This clinic accepts referrals from all over the UK for couples who have suffered two or more miscarriages.

RESULTS

Seventeen participants were interviewed: 14 women and 3 male partners. Six main themes were identified from the data. Three related to the women's lived experience of recurrent miscarriage (emotions in pregnancy, confidence in their bodies, expectations and coping strategies) and three related to the clinical support offered by the NHS service (impact of early pregnancy scanning, effect of the COVID-19 pandemic and cytogenetic investigations).

CONCLUSIONS

Pregnancy following recurrent miscarriage is extremely difficult. Recurrent miscarriage specialist services can provide couples with support and access to early pregnancy scanning, which can make the first trimester of pregnancy manageable. Partners should not be excluded from the clinic as it can result in a feeling of disconnect. Cytogenetic testing of pregnancy tissue can offer couples with recurrent miscarriage closure after pregnancy loss and is a desired investigation.

Predicting risk of blastocyst aneuploidy among women with previous aneuploid pregnancy loss: a multicenter-data-based multivariable model

STUDY QUESTION

Can blastocyst aneuploidy be predicted for patients with previous aneuploid pregnancy loss (PAPL) and receiving preimplantation genetic testing for aneuploidy (PGT-A)?

SUMMARY ANSWER

Multivariable logistic regression models were established to predict high risk of blastocyst aneuploidy using four identified factors, presenting good predictive performance.

WHAT IS KNOWN ALREADY

Aneuploidy is the most common embryonic chromosomal abnormality leading to pregnancy loss. Several studies have demonstrated a higher embryo aneuploidy rate in patients with PAPL, which has suggested that PGT-A should have benefits in PAPL patients intending to improve their pregnancy outcomes. However, recent studies have failed to demonstrate the efficacy of PGT-A for PAPL patients. One possible way to improve the efficacy is to predict the risk of blastocyst aneuploidy risk in order to identify the specific PAPL population who may benefit from PGT-A.

STUDY DESIGN, SIZE, DURATION

We conducted a multicenter retrospective cohort study based on data analysis of 1119 patients receiving PGT-A in three reproductive medical centers of university affiliated teaching hospitals during January 2014 to June 2020. A cohort of 550 patients who had one to three PAPL(s) were included in the PAPL group. In addition, 569 patients with monogenic diseases without pregnancy loss were taken as the non-PAPL group.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PGT-A was conducted using single nucleotide polymorphism microarrays and next-generation sequencing. Aneuploidy rates in Day 5 blastocysts of each patient were calculated and high-risk aneuploidy was defined as a rate of ≥50%. Candidate risk factors for high-risk aneuploidy were selected using the Akaike information criterion and were subsequently included in multivariable logistic regression models. Overall predictive accuracy was assessed using the confusion matrix, discrimination by area under the receiver operating characteristic curve (AUC), and calibration by plotting the predicted probabilities versus the observed probabilities. Statistical significance was set at P < 0.05.

MAIN RESULTS AND THE ROLE OF CHANCE

Blastocyst aneuploidy rates were 30 ± 25% and 21 ± 19% for PAPL and non-PAPL groups, respectively. Maternal age (odds ratio (OR) = 1.31, 95% CI 1.24-1.39, P < 0.001), number of PAPLs (OR = 1.40, 95% CI 1.05-1.86, P = 0.02), estradiol level on the ovulation trigger day (OR = 0.47, 95% CI 0.30-0.73, P < 0.001), and blastocyst formation rate (OR = 0.13, 95% CI 0.03-0.50, P = 0.003) were associated with high-risk of blastocyst aneuploidy. The predictive model based on the above four variables yielded AUCs of 0.80 using the training dataset and 0.83 using the test dataset, with average and maximal discrepancies of 2.89% and 12.76% for the training dataset, and 0.98% and 5.49% for the test dataset, respectively.

LIMITATIONS, REASONS FOR CAUTION

Our conclusions might not be compatible with those having fewer than four biopsied blastocysts and diminished ovarian reserves, since all of the included patients had four or more biopsied blastocysts and had exhibited good ovarian reserves.

WIDER IMPLICATIONS OF THE FINDINGS

The developed predictive model is critical for counseling PAPL patients before PGT-A by considering maternal age, number of PAPLs, estradiol levels on the ovulation trigger day, and the blastocyst formation rate. This prediction model achieves good risk stratification and so may be useful for identifying PAPL patients who may have higher risk of blastocyst aneuploidy and can therefore acquire better pregnancy outcomes by PGT-A.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China under Grant (81871159). No competing interest existed in the study.

TRIAL REGISTRATION NUMBER

N/A.

Prevalence of chromosomal alterations in first-trimester spontaneous pregnancy loss

Pregnancy loss is often caused by chromosomal abnormalities of the conceptus. The prevalence of these abnormalities and the allocation of (ab)normal cells in embryonic and placental lineages during intrauterine development remain elusive. In this study, we analyzed 1,745 spontaneous pregnancy losses and found that roughly half (50.4%) of the products of conception (POCs) were karyotypically abnormal, with maternal and paternal age independently contributing to the increased genomic aberration rate. We applied genome haplarithmisis to a subset of 94 pregnancy losses with normal parental and POC karyotypes. Genotyping of parental DNA as well as POC extra-embryonic mesoderm and chorionic villi DNA, representing embryonic and trophoblastic tissues, enabled characterization of the genomic landscape of both lineages. Of these pregnancy losses, 35.1% had chromosomal aberrations not previously detected by karyotyping, increasing the rate of aberrations of pregnancy losses to 67.8% by extrapolation. In contrast to viable pregnancies where mosaic chromosomal abnormalities are often restricted to chorionic villi, such as confined placental mosaicism, we found a higher degree of mosaic chromosomal imbalances in extra-embryonic mesoderm rather than chorionic villi. Our results stress the importance of scrutinizing the full allelic architecture of genomic abnormalities in pregnancy loss to improve clinical management and basic research of this devastating condition.

Recurrent MiscarriageGreen-top Guideline No. 17

In this guideline, recurrent miscarriage has been defined as three or more first trimester miscarriages. However, clinicians are encouraged to use their clinical discretion to recommend extensive evaluation after two first trimester miscarriages, if there is a suspicion that the miscarriages are of pathological and not of sporadic nature. Women with recurrent miscarriage should be offered testing for acquired thrombophilia, particularly for lupus anticoagulant and anticardiolipin antibodies, prior to pregnancy. [Grade C] Women with second trimester miscarriage may be offered testing for Factor V Leiden, prothrombin gene mutation and protein S deficiency, ideally within a research context. [Grade C] Inherited thrombophilias have a weak association with recurrent miscarriage. Routine testing for protein C, antithrombin deficiency and methylenetetrahydrofolate reductase mutation is not recommended. [Grade C] Cytogenetic analysis should be offered on pregnancy tissue of the third and subsequent miscarriage(s) and in any second trimester miscarriage. [Grade D] Parental peripheral blood karyotyping should be offered for couples in whom testing of pregnancy tissue reports an unbalanced structural chromosomal abnormality [Grade D] or there is unsuccessful or no pregnancy tissue available for testing. [GPP] Women with recurrent miscarriage should be offered assessment for congenital uterine anomalies, ideally with 3D ultrasound. [Grade B] Women with recurrent miscarriage should be offered thyroid function tests and assessment for thyroid peroxidase (TPO) antibodies. [Grade C] Women with recurrent miscarriage should not be routinely offered immunological screening (such as HLA, cytokine and natural killer cell tests), infection screening or sperm DNA testing outside a research context. [Grade C] Women with recurrent miscarriage should be advised to maintain a BMI between 19 and 25 kg/m2 , smoking cessation, limit alcohol consumption and limit caffeine to less than 200 mg/day. [Grade D] For women diagnosed with antiphospholipid syndrome, aspirin and heparin should be offered from a positive test until at least 34 weeks of gestation, following discussion of potential benefits versus risks. [Grade B] Aspirin and/or heparin should not be given to women with unexplained recurrent miscarriage. [Grade B] There are currently insufficient data to support the routine use of PGT-A for couples with unexplained recurrent miscarriage, while the treatment may carry a significant cost and potential risk. [Grade C] Resection of a uterine septum should be considered for women with recurrent first or second trimester miscarriage, ideally within an appropriate audit or research context. [Grade C] Thyroxine supplementation is not routinely recommended for euthyroid women with TPO who have a history of miscarriage. [Grade A] Progestogen supplementation should be considered in women with recurrent miscarriage who present with bleeding in early pregnancy (for example 400 mg micronised vaginal progesterone twice daily at the time of bleeding until 16 weeks of gestation). [Grade B] Women with unexplained recurrent miscarriage should be offered supportive care, ideally in the setting of a dedicated recurrent miscarriage clinic. [Grade C].

The effects of first-trimester subchorionic hematoma on pregnancy outcomes: a retrospective cohort study

BACKGROUND

Although first-trimester subchorionic hematoma (SCH) always concerns expectant parents, its clinical significance remains controversial. This study aimed to examine the relationship between SCH and its association with subsequent miscarriage and other perinatal outcomes in singleton pregnancies.

METHODS

We conducted a retrospective cohort study including 43,660 women who underwent routine prenatal care since the first trimester and then were followed up for maternal and neonatal outcomes. SCH was detected in the first-trimester ultrasound examinations. Robust Poisson regression was used to estimate adjusted risk associations of SCH with maternal and neonatal outcomes.

RESULTS

A total of 815 (1.87%) SCH cases were detected in the first-trimester ultrasound examinations. The rate of miscarriage was statistically significantly higher in women with SCH than without [35.21% vs. 23.92%, P < 0.01; adjusted relative risk (RR):1.44, 95% confidence interval (CI): 1.31-1.58]. Subgroup analysis of women with SCH showed a clear trend that the earlier SCH occurred, the higher the risk of miscarriage was [adjusted RR (95% CI) for onset at the gestational weeks of 8-9, 6-7, and < 6 vs. ≥ 10: 1.30 (0.69-2.46), 2.33 (1.28-4.23), and 4.18 (2.30-7.58), respectively; Ptrend < 0.01]. In addition, women with SCH volume ≥ 1 ml showed higher risk than did those with SCH volume < 1 ml [adjusted RR (95% CI) for 1-4.9 ml, and ≥ 5 ml vs. < 1 ml: 1.36 (1.10-1.68) and 1.56 (1.18-2.07), respectively]. There was no statistically significant difference in the rates of other pregnancy outcomes between women with and without SCH.

CONCLUSIONS

First-trimester SCH, particularly when characterized by early presence and large size, might significantly increase the risk of miscarriage. Data from this study suggest no associations between SCH and other maternal and neonatal outcomes.

The Clinical Significance of Embryonic Chromosomal Errors in Recurrent Pregnancy Loss: an Analysis of 1107 Miscarriages

The objective of this study was to characterize the relationship between embryonic chromosomal errors in the products of conception (POC) and maternal age, gestational age (GA) of pregnancy loss, and findings on routine recurrent pregnancy loss (RPL) workup. This is a retrospective cohort study of women with a history of ≥ 2 pregnancy losses and who underwent cytogenetic testing on the POC of a subsequent pregnancy loss at an academic tertiary RPL referral center. The association between the odds of embryonic chromosomal errors in POC and maternal age, GA of pregnancy loss, as well as RPL work up findings was investigated. A total of 1107 miscarriages were analyzed from 741 women. There was an overall linear relationship between embryonic chromosomal errors and maternal age, with a nearly twofold increase in the odds of chromosomal error with every 5-year increase in maternal age (P < 0.0001). The association between chromosomal errors and GA was also linear (P = 0.0001), with most losses having no chromosomal errors after 13 weeks' gestation. Women with ≥ 1 positive findings on routine RPL diagnostic workup had lower odds of embryonic chromosomal errors compared to those with a normal workup [OR 0.57 (95% CI = 0.41-0.80)]. Notably, the estimated prevalence of chromosomal error remained high (> 60%) in women ≥ 35 years old irrespective of findings on routine evaluation. While embryonic chromosomal errors were associated with advanced maternal age, early GA of loss, and a negative routine RPL evaluation, the prevalence of chromosomal errors remained high in all subpopulations. These findings suggest that primary cytogenetic testing on POCs should be offered at the time of second and subsequent pregnancy losses in all RPL patients.

Update on preimplantation genetic testing for aneuploidy and outcomes of embryos with mosaic results

Preimplantation genetic testing for aneuploidy (PGT-A) is used as a frequent add-on for in-vitro fertilization (IVF) to improve clinical outcomes. The purpose is to select a euploid embryo following chromosomal testing on embryo biopsies. The current practice includes comprehensive chromosome screening (CCS) technology applied on trophectoderm (TE) biopsies. Despite its widespread use, PGT-A remains a controversial topic mainly because all of the RCTs comprised only good prognosis patients with 2 or more blastocysts available; hence the results are not generalizable to all groups of patients. Furthermore, with the introduction of the highly-sensitive platforms into clinical practice (i.e. next-generation sequencing [NGS]), a result consistent with intermediate copy number surfaced and is termed "Mosaic," consistent with a mixture of euploid and aneuploid cells within the biopsy sample. The optimal disposition and management of embryos with mosaic results is still an open question, as many 'mosaics' generated healthy live births with no identifiable congenital anomalies. The present article provides a complete and comprehensive up-to-date review on PGT-A. It discusses in detail the findings of all the published RCTs on PGT-A with CCS, comments on the subject of "mosaicism" and its current management, and describes the latest technique of non-invasive PGT-A.

What proportion of couples with a history of recurrent pregnancy loss and with a balanced rearrangement in one parent can potentially be identified through cell-free DNA genotyping?

BACKGROUND

Balanced chromosome aberrations are reported in about 1:30 couples with recurrent pregnancy loss (RPL). Karyotyping of both parents is necessary to identify these aberrations. Genome-wide non-invasive prenatal testing (NIPT) in case of recurrent pregnancy loss could be a more efficient way to identify couples at increased risk for carrying a balanced chromosome rearrangement. The aim of this study was to evaluate whether the potential fetal imbalances caused by parental balanced aberrations detected in our center are large enough to be detectable by genome-wide non-invasive prenatal testing (NIPT).

MATERIAL AND METHODS

From January 1970 until May 2020 our laboratory received 30,863 unique requests for karyotyping due to RPL. We have identified 16,045 couples and evaluated all abnormal cytogenetic results to assess the minimal size of the involved chromosomal segments in potential unbalanced products of the rearrangements.

RESULTS

In the presented cohort we detected 277 aberrant balanced translocations/inversions in females and 185 in males amongst 16,045 couples with RPL, which can be translated to a risk of 1:35 (2.9%, 95% CI 2.6-3.2%). Our study showed that the vast majority (98.7%, 95% CI 97.1-99.5%) of these balanced aberrations will potentially cause a fetal imbalance > 10 Mb, which is detectable with genome-wide NIPT if it was performed during one of the miscarriages.

CONCLUSIONS

Our study suggests that genome-wide NIPT is able to reveal most unbalanced products of balanced chromosomal rearrangements carried by couples with RPL and therefore can potentially identify balanced chromosomal aberration carriers. Moreover, our data suggest that these couples can be offered NIPT in case they decline invasive testing in future pregnancies.

Analysis of chromosomal structural variations in patients with recurrent spontaneous abortion using optical genome mapping

Background and aims: Certain chromosomal structural variations (SVs) in biological parents can lead to recurrent spontaneous abortions (RSAs). Unequal crossing over during meiosis can result in the unbalanced rearrangement of gamete chromosomes such as duplication or deletion. Unfortunately, routine techniques such as karyotyping, fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and copy number variation sequencing (CNV-seq) cannot detect all types of SVs. In this study, we show that optical genome mapping (OGM) quickly and accurately detects SVs for RSA patients with a high resolution and provides more information about the breakpoint regions at gene level. Methods: Seven couples who had suffered RSA with unbalanced chromosomal rearrangements of aborted embryos were recruited, and ultra-high molecular weight (UHMW) DNA was isolated from their peripheral blood. The consensus genome map was created by de novo assembly on the Bionano Solve data analysis software. SVs and breakpoints were identified via alignments of the reference genome GRCh38/hg38. The exact breakpoint sequences were verified using either Oxford Nanopore sequencing or Sanger sequencing. Results: Various SVs in the recruited couples were successfully detected by OGM. Also, additional complex chromosomal rearrangement (CCRs) and four cryptic balanced reciprocal translocations (BRTs) were revealed, further refining the underlying genetic causes of RSA. Two of the disrupted genes identified in this study, FOXK2 [46,XY,t(7; 17)(q31.3; q25)] and PLXDC2 [46,XX,t(10; 16)(p12.31; q23.1)], had been previously shown to be associated with male fertility and embryo transit. Conclusion: OGM accurately detects chromosomal SVs, especially cryptic BRTs and CCRs. It is a useful complement to routine human genetic diagnostics, such as karyotyping, and detects cryptic BRTs and CCRs more accurately than routine genetic diagnostics.

Ubiquitin-specific protease 7 prevents recurrent spontaneous abortion by targeting enhancer of zeste homolog 2 to regulate trophoblast proliferation, apoptosis, migration, and invasion through the Wnt/β-catenin pathway†

Trophoblasts are significant components of the placenta and play crucial roles in maternal-fetal crosstalk. Adequate trophoblast migration and invasion are essential for embryo implantation and healthy pregnancy. Ubiquitin-specific protease 7 (USP7), a member of the deubiquitinating enzyme family, regulates the processes of migration and invasion in multiple tumor cells. However, the effects of USP7 on trophoblasts and its possible mechanism in the development of recurrent spontaneous abortion (RSA) are still unclear. In this study, we analyzed the expression of USP7 in villous tissues obtained from RSA patients and healthy controls, and then GNE-6776 (a USP7-specific inhibitor) and USP7 siRNA were used in a trophoblast cell line, HTR-8/SVneo, to further assess the effect of USP7 on the biological function of trophoblasts. Our results provide convincing evidence that USP7 is downregulated in the placental villous tissues of RSA patients. USP7 was found to have a crucial role in the proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) process of trophoblast cells. Further experiments revealed that USP7 directly interacted with the enhancer of zeste homolog 2 (EZH2) and regulated the Wnt/β-catenin signaling pathway in trophoblasts. Taken together, these findings indicate the vital role of USP7 in regulating trophoblast proliferation, migration and invasion, thus affecting the pathogenesis of RSA, providing new insights into the important role of USP7 in the maternal-fetal interface.

Cervicovaginal microbiome in patients with recurrent pregnancy loss

There have been few studies concerning an association between unexplained recurrent pregnancy loss (RPL) and the microbiome. A recent study including 67 patients demonstrated that an increase in Ureaplasma species in the endometrium raised the risk of miscarriage with an euploid karyotype. While endometrial sampling is invasive, cervicovaginal sampling is not. We compared vaginal and cervical microbiomes with a 16 S ribosomal RNA sequence between 88 patients with unexplained RPL and 17 healthy women with no history of miscarriage. We prospectively assessed risk factors for maternal colonization at a subsequent miscarriage without an aneuploid karyotype in patients. Cervicovaginal bacteria were dominated by Lactobacillus iners, Gardnerella vaginalis, Atopobium vaginae and Bifidobacterium breve in Japanese population. The proportions of Delftia and unknown bacteria in the cervix were significantly higher in patients with RPL than in controls. Streptococcus, Microbacterium, Delftia, Anaerobacillus and Chloroplast in the cervix were significantly higher in patients with a history of chorioamnionitis compared to the controls. The abundance of Cutibacterium and Anaerobacillus in the cervix was significantly higher in patients who had subsequently miscarried compared to those who gave birth. The miscarriage rate in patients with higher proportions of both Cutibacterium and Anaerobacillus (66.7%, 2/3) was significantly greater than that of patients who lacked these bacteria (9.2%, 6/65, adjusted odds ratio 16.90, 95% confidence interval 1.27-225.47, p = 0.032). The presence of certain bacteria could be a predictor of subsequent miscarriage without an aneuploid karyotype. The cervicovaginal microbiome might be useful for investigating a possible cause of RPL.

The association between chronic deciduitis and recurrent pregnancy loss

Chronic deciduitis (CD) is defined as the presence of lymphocytes or plasma cells in decidual tissue. CD suggests the presence of chronic endometritis (CE) which is associated with recurrent pregnancy loss (RPL). In this study, we examined the role CD plays in RPL patients with aneuploid and euploid miscarriage. The frequency of CD in 49 RPL patients (22 euploid and 27 aneuploid miscarriages) and 17 control women was assessed and the subsequent live birth rate (LBR) in the presence and absence of CD were compared. When only one CD138-positive endometrial stromal plasma cell (ESPC) was found per high-power field (HPF), we diagnosed small-positive CD (Grade 1). When a cluster of two or more CD138-positive ESPCs was found per HPF, we diagnosed it as CD Grade 2. The prevalence of Grade 1 was 18.2% (4/22) in patients with euploid miscarriage, 37.0% (10/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. The prevalence of Grade 2 was 45.5% (10/22) in patients with euploid miscarriage, 55.6% (15/27) in patients with aneuploid miscarriage and 23.5% (4/17) in control women. There was a significant difference in the prevalence of CD (p = 0.015). The LBR of patients with CD was similar to that of patients without CD. CD was associated with RPL, especially in patients with aneuploid miscarriage. However, since there was no difference in the LBR of patients with or without CD in the next pregnancy, it was unclear whether CD was a contributing cause of RPL.

Double vitrification-warming cycles, coupled with blastocyst biopsy, impair live birth but do not affect neonatal outcomes

OBJECTIVE

To identify whether the transfer of blastocysts that have been vitrified, thawed, biopsied, revitrified, and subsequently rethawed affects clinical outcome and neonatal outcome.

METHODS

A retrospective study was conducted in a single assisted reproduction technology center from September 2016 to March 2021. Women undergoing single frozen euploid blastocysts transfer were stratified into two groups based on number of vitrification-thawing cycles: single vitrification coupled with single biopsy (group A, n = 177) and double vitrification coupled with single biopsy (group B, n = 30). Pregnancy and perinatal outcomes of the two groups were compared.

RESULTS

Clinical pregnancy rates were similar between the two groups. Group B was associated with an increased likelihood of live birth when compared with group A by different multivariable analysis models (model 1: odds ratio, 0.42 [95% confidence interval, 0.18-0.97], P = 0.041; model 2: odds ratio, 0.38 [95% confidence interval, 0.16-0.92], P = 0.033). No major obstetrical complication was reported in the two groups and only one malformation live birth was reported in group A.

CONCLUSION

The procedure of double vitrification-warming cycles, coupled with single biopsy, increases pregnancy loss and ultimately diminishes live birth but does not affect perinatal outcome. Future studies with a larger sample size would help to validate the results.

The Progress of Research on Genetic Factors of Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is both mental and physical health problem affecting about 1-5% of women of childbearing age. The etiology of RPL is complex, involving chromosomal abnormalities, autoimmune diseases, metabolic disorders, and endometrial dysfunction. The causes of abortion are still unknown in more than 50% of these cases. With the development of science and technology, an increasing number of scholars focus on this field and find that genetic factors may play an essential role in unexplained RPL, such as embolism-related genes, immune factor-related genes, and chromosomal numeric, and structural variation. This review summarizes the genetic factors associated with RPL, including genetic mutations and genetic polymorphisms, chromosomal variants, and chromosomal polymorphisms. Many related genetic factors have been found to be demographically and geographically relevant, some of which can be used for risk prediction or screening for the etiology of RPL. However, it is difficult to predict and prevent RPL due to uncertain pathogenesis and highly variable clinical presentation. Therefore, the genetic factors of RPL still need plentiful research to obtain a more accurate understanding of its pathogenesis and to provide more detection means for the screening and prevention of RPL.

Autophagy markers are dysregulated in the endometrial tissues of patients with unexplained repeated implantation failure

Endometrium decidualization is a complex biological process, which includes the interplay of transcription factors, cytokines, cell cycle regulators, and other signaling pathways. However, the underlying molecular mechanisms of this process are not fully elucidated to date. In this study, we aimed to investigate the possible association between autophagy and recurrent implantation failure (RIF). A total of 81 genes were downregulated and 231 genes were upregulated in the RIF group compared with the control group, and the differences were statistically significant (p < 0.05). Further, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were analyzed, and we found that some autophagy markers, for example, LC3-II, LAMP2, and HIF-1α were significantly increased, whereas P62 was drastically downregulated in the RIF group. Similar results were observed in proteins level; and the autophagy puncta were also markedly enhanced in the endometrial tissues of RIF patients. Autophagy is closely associated with the RIF occurs and may be involved in the pathogenesis of RIF.

Tumour necrosis factor inhibitor combined with intravenous immunoglobulin and heparin for treatment of recurrent spontaneous abortion: A two-centre, retrospective, cohort study

WHAT IS KNOWN AND OBJECTIVE

Immune disorder is a key trigger of recurrent spontaneous abortion (RSA); meanwhile, tumour necrosis factor inhibitor (TNFi) is a fundamental therapeutic for multiple immune and inflammatory diseases. Hence, this real-world study aimed to explore the efficacy and safety of TNFi combined with intravenous immunoglobin (IVIG) and heparin therapy in RSA patients.

METHODS

A total of 105 RSA patients who received TNFi+IVIG+Heparin (enoxaparin) (n = 48) or IVIG+Heparin (enoxaparin) (n = 57) were retrospectively included in this two-centre cohort study.

RESULTS AND DISCUSSION

The live birth rate of RSA patients in the TNFi+IVIG+heparin group was 72.9% (95% confidence interval [CI]: 69.6%-85.9%). Besides, the live birth rate in the IVIG+heparin group was 52.6% (95% CI: 42.8%-62.4%). By comparison, the live birth rate was higher in the TNFi+IVIG+heparin group compared to the IVIG+heparin group (p = 0.033). After adjustment by the multivariate logistic regression model using the enter method, TNFi+IVIG+Heparin was also superior to IVIG+Heparin regarding increased live birth rate (odds ratio [OR] = 2.941, p = 0.015). Moreover, TNFi+IVIG+Heparin (vs. IVIG+Heparin) also served as an independent factor for increased live birth rate (OR = 2.423, p = 0.035) by the forward stepwise method in the multivariate analysis. Gestational weeks at delivery (38.3 ± 1.3 vs. 37.7 ± 2.0 weeks, p = 0.155), newborn weight (3123.9 ± 332.1 vs. 3056.6 ± 287.4 g, p = 0.390), Apgar score of newborns (9.8 ± 0.5 vs. 9.7 ± 0.7, p = 0.271) were of no difference between TNFi+IVIG+Heparin and IVIG+Heparin groups. In terms of safety profile, the adverse events were of no difference between the TNFi+IVIG+Heparin and the IVIG+Heparin groups (all p > 0.05), either.

WHAT IS NEW AND CONCLUSION

TNFi combined with IVIG and heparin therapy improves the live birth rate but does not elevate the adverse events compared to IVIG and heparin therapy in RSA patients.

Systematic review of subsequent pregnancy outcomes in couples with parental abnormal chromosomal karyotypes and recurrent pregnancy loss

OBJECTIVE

To evaluate the current evidence of pregnancy outcomes among couples with recurrent pregnancy loss (RPL) with abnormal karyotypes vs. those with normal karyotypes and among couples with RPL and abnormal karyotypes after receiving expectant management vs. preimplantation genetic diagnosis (PGD).

DESIGN

Systematic review and meta-analysis.

SETTING

Academic medical centers.

PATIENT(S)

Pregnancy outcomes in 6,301 couples with RPL who conceived without medical intervention in 11 studies were analyzed. However, only 2 studies addressed the outcomes of couples with RPL and abnormal karyotypes after expectant management (75 cases) vs. PGD (50 cases).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The pregnancy outcomes in couples with RPL with abnormal and normal karyotypes across included studies were evaluated.

RESULT(S)

Compared with those with a normal karyotype, a significantly lower first pregnancy live birth rate (LBR) was found in couples with RPL with abnormal karyotypes (58.5% vs. 71.9%; odds ratio [OR], 0.55; 95% confidence interval [CI], 0.46-0.65; I² =27%). A markedly decreased first pregnancy LBR was found in couples with a translocation (52.9% vs. 72.4%; OR, 0.44; 95% CI, 0.31-0.61; I² =33%) but not in couples with an inversion. However, the differences in accumulated LBR (81.4% vs. 74.8%; OR, 0.96; 95% CI, 0.90-1.03; I² = 0) were nonsignificant, whereas the miscarriage rate was distinctly higher in couples with RPL and abnormal karyotypes (53.0% vs. 34.7%; OR, 2.21; 95% CI, 1.69-2.89; I² = 0). Compared with those who chose expectant management, differences in accumulated LBR were nonsignificant (60% vs. 68%; OR, 0.55; 95% CI, 0.11-2.62; I² =71%), whereas the miscarriage rate (24% vs. 65.3%; OR, 0.15; 95% CI, 0.04-0.51; I² = 45) was markedly low in couples with RPL and abnormal karyotypes who chose PGD.

CONCLUSION(S)

Couples with RPL and abnormal karyotypes had a higher miscarriage rate than couples with normal karyotypes but achieved a noninferior accumulated LBR through multiple conception attempts. In couples with RPL and abnormal karyotypes, PGD treatment did not increase the accumulated LBR but markedly reduced miscarriage rate compared with expectant management.

Antiphospholipid Antibodies in Pregnancy: Maternal and Neonatal Implications

Antiphospholipid antibodies (aPL Abs) have long been associated with the occurrence of certain specific pregnancy morbidities, affecting both mother and fetus. Antithrombotic-based prophylactic regimens are the standard of care. Their intensity is modulated by the thrombotic history and has greatly improved the prognosis related to spontaneous morbidity. Observational studies show that this treatment is still associated with the persistence of excess of late-pregnancy placental diseases, calling for new or complementary developments, yet to be validated. Rigorous prospective multicentric validation of clinical and laboratory parameters capable of identifying those women and fetuses at a risk of pejorative evolution, thus early prognosis, is a priority issue. These will make it possible to develop customized treatments and test them. Furthermore, there are still concerns, particularly neurodevelopmental ones, about children born to aPL Ab-positive mothers, and clarification based on regular, more systematic evaluations is required. Even after pregnancy, women with a pure obstetrical antiphospholipid syndrome are at a greater risk of venous and arterial thrombosis over time, and prevention needs to be improved. These women also appear to develop more psychiatric and mood disorders. Central nervous system imaging using high-resolution techniques has shown subtle impairments in the white matter, associated with the most pathogenic aPL Abs and the clinical significance of this is under investigation. These mothers also seem to develop an excess of cancers. The systemic impact of aPL Abs is gradually being suspected, although this requires further evidence, and prevention should be envisaged.

Two kinds of embryo research: four case examples

There are ethical obligations to conduct research that contributes to generalisable knowledge and improves reproductive health, and this should include embryo research in jurisdictions where it is permitted. Often, the controversial nature of embryo research can alarm ethics committee members, which can unnecessarily delay important research that can potentially improve fertility for patients and society. Such delay is ethically unjustified. Moreover, countries such as the UK, Australia and Singapore have legislation which unnecessarily captures low-risk research, such as observational research, in an often cumbersome and protracted review process. Such countries should revise such legislation to better facilitate low-risk embryo research.We introduce a philosophical distinction to help decision-makers more efficiently identify higher risk embryo research from that which presents no more risks to persons than other types of tissue research. That distinction is between future person embryo research and non-future person embryo research. We apply this distinction to four examples of embryo research that might be presented to ethics committees.Embryo research is most controversial and deserving of detailed scrutiny when it potentially affects a future person. Where it does not, it should generally require less ethical scrutiny. We explore a variety of ways in which research can affect a future person, including by deriving information about that person, and manipulating eggs or sperm before an embryo is created.

Characteristic DNA methylation profiles of chorionic villi in recurrent miscarriage

Dysregulation of transcriptional programs that are tightly regulated by DNA methylation during placental and fetal development at different gestational stages, may cause recurrent miscarriage. Here, we examined genome-wide DNA methylation in chorionic villi and decidual tissues from patients suffering RM and from healthy women who had undergone artificial abortion (n = 5 each). We found that 13,426 and 5816 CpG sites were differentially methylated in chorionic villi and decidua, respectively. DNA methylation profiles of chorionic villi, but not decidua, in RM patients was clearly distinct from AA controls. Among the differentially methylated genes, the enhancer region of SPATS2L was significantly more highly methylated in RM patients (n = 19) than AA controls (n = 19; mean methylation level, 52.0%-vs.-28.9%, P < 0.001), resulting in reduced expression of SPATS2L protein in the former. Functionally, depletion of SPATS2L in extravillous trophoblast cells decreased their invasion and migration abilities. Our data indicate that particularly the chorionic villi in RM patients exhibit distinct DNA methylation profiles compared with normal pregnancies and that this changed DNA methylation status may impede the progression of embryo development via the altered expression of genes such as SPATS2L in the villi.

Non-coding RNAs and their cross-talks impacting reproductive health of women

Non-coding RNAs (ncRNAs) work as crucial posttranscriptional modulators of gene expression regulating a wide array of biological processes that impact normal physiology, including reproductive health. The health of women, especially reproductive health, is now a prime focus of society that ensures the females' overall physical, social, and mental well-being. Furthermore, there has been a growing cognizance of ncRNAs' possible applications in diagnostics and therapeutics of dreaded diseases. Hence, understanding the functions and mode of actions of ncRNAs in the context of women's health will allow us to develop effective prognostic and therapeutic strategies that will enhance the quality of life of women. Herein, we summarize recent progress on ncRNAs, such as microRNAs (miRNAs) and long ncRNAs (lncRNAs), and their implications in reproductive health by tying the knot with lifestyle factors that affect fertility complications, pregnancy outcomes, and so forth. We also discourse the interplay among the RNA species, especially miRNAs, lncRNAs, and protein-coding RNAs, through the competing endogenous RNA regulations in diseases of women associated with maternal and fetal health. This review provides new perspectives correlating ncRNAs, lifestyle, and reproductive health of women, which will attract future studies to improve women's lives. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

The implications of exosomes in pregnancy: emerging as new diagnostic markers and therapeutics targets

Extracellular vehicles (EVs) are a heterogeneous group of cell and membranous particles originating from different cell compartments. EVs participate in many essential physiological functions and mediate fetal-maternal communications. Exosomes are the smallest unit of EVs, which are delivered to the extracellular space. Exosomes can be released by the umbilical cord, placenta, amniotic fluid, and amniotic membranes and are involved in angiogenesis, endothelial cell migration, and embryo implantation. Also, various diseases such as gestational hypertension, gestational diabetes mellitus (GDM), preterm birth, and fetal growth restriction can be related to the content of placental exosomes during pregnancy. Due to exosomes' ability to transport signaling molecules and their effect on sperm function, they can also play a role in male and female infertility. In the new insight, exosomal miRNA can diagnose and treat infertilities disorders. In this review, we focused on the functions of exosomes during pregnancy. Video abstract.

Evaluating the application value of NGS-based PGT-A by screening cryopreserved MDA products of embryos from PGT-M cycles with known transfer outcomes

PURPOSE

To determine the application value of next-generation sequencing (NGS)-based preimplantation genetic testing for aneuploidies (PGT-A).

METHODS

We conducted a retrospective case-control study on a cohort of frozen-thawed embryo transfer (FET) cycles following preimplantation genetic testing for monogenic disorders (PGT-M) between 2014 and 2017. Cycles that produced live births or early miscarriages were divided into live birth group (n = 76) or miscarriage group (n = 19), respectively. The NGS-based aneuploidy screening was performed on the multiple displacement amplification (MDA) products of the embryonic trophectoderm biopsy samples that were cryopreserved following PGT-M.

RESULTS

In the live birth group, 75% (57/76) embryos were euploid and 14.5% (11/76) were aneuploid. The remaining 10.5% (8/76) embryos were NGS-classified mosaic with the high- (≥ 50%) and low-level (< 50%) mosaicism rates at 7.9% (6/76) and 2.6% (2/76), respectively. In the miscarriage group, only 23.5% (4/17) embryos were aneuploid, while 58.8% (10/17) were euploid and 17.6% (3/17) were NGS-classified mosaic with the high- and low-level mosaicism rates at 11.8% (2/17) and 5.9% (1/17), respectively. For live birth and miscarriage groups, the transferable rate was 82.9% (63/76) and 70.6% (12/17), respectively, whereas the untransferable rate was 17.1% (13/76) and 29.4% (5/17), respectively.

CONCLUSION

The application of NGS-based PGT-A remains questionable, as it may cause at least one in six embryos with reproductive potential to be discarded and prevent miscarriage in less than one in three embryos in single-gene disease carriers.

Analysis of parental abnormal chromosomal karyotype and subsequent live births in Chinese couples with recurrent pregnancy loss

The frequency and distribution of chromosomal abnormalities and the impact of parental chromosomal aberration on the pregnancy outcomes of couples with recurrent pregnancy loss remains controversial. 3235 RPL couples who experienced two or more miscarriages before 20 weeks were diagnosed in our tertiary referral hospital during 2008–2018 and included in the single-center retrospective cohort study covering a 10-year period. Chromosome aberration was detected in 121 (3.74%) among 3235 RPL couples which included 75 female and 46 male cases at an individual level. 101 cases were structural aberrations including balanced translocations in 46(38.0%) cases, Robertsonian translocations in 13(10.7%) cases, inversions in 42(34.7%) cases and 20(16.5%) cases were numerical aberrations. 121 carriers and 428 non-carriers were followed up for two years, 55 carriers and 229 non-carriers were subsequent pregnant after diagnosis by natural conception or intrauterine insemination. The frequency of carriers to have a health newborn was not significantly different with non-carriers (72.7% vs. 71.2%, adjusted P = 0.968). This study described the majority of carriers were balanced translocations and chromosome aberrations had a limited influence on live birth rate from the present data. The results of the study also remind us that natural conception may be also a good alternative rather than PGD (Pre-implantation Genetic Diagnosis) which is common in many other reproductive centers for such patients.

Investigating the role of EGF-CFC gene family in recurrent pregnancy loss through bioinformatics and molecular approaches

Recurrent pregnancy loss (RPL) is the most common reproductive failure, reaching 1-5% of women throughout their lives, and having unknown etiology in 50% of the cases. In humans, EGF-CFC1 (Epidermal Growth Factors & Cripto/FRL-1/Cryptic) gene family is composed by TDGF1 and CFC1, two developmental genes. The aim of this study was to investigate the role of EGF-CFC on RPL. To this, multiple approaches were performed; we conducted an expression analysis of TDGF1 and CFC1 using publicly available data from Gene Omnibus Expression (GEO), systems biology analyses and functional prediction; and a molecular analysis carried out in a case-control study. Our GEO analysis showed a decrease in TDGF1 expression in the endometrium (p=0.049) and CFC1 expression in placenta (p=0.015) of women with RPL. Network analysis, gene ontology and literature pointed to a strong connection between EGF-CFC1 gene family to pathways that play key roles during pregnancy, including TGF-β, c-Src/MAPK/AKT, Notch, TNFα, IFNγ and IL-6. A pathogenicity score developed for this gene family showed that the c.-14+1429T>C (rs3806702) variant in the TDGF1 and the p.Arg47Gln (rs201431919) variant in CFC1 gene would be the ones with the highest deleterious effect for RPL. In the case-control study, which involved 149 women with RPL and 159 controls, no statistical difference was observed in the allele and genotype distributions of the variants studied in the two groups. In this study, we performed extensive bioinformatics analysis for biomarker prioritization followed by experimental validation of proposed selected markers. Although there is no statistical difference in the frequencies of these variants between RPL and controls, the expression analysis results suggest that TDGF1 and CFC1 genes might play a role in RPL. In addition, systems biology analyzes raise the hypothesis that genes in other signaling pathways that may be related to RPL as good candidates for future studies.Abbreviations RPL: recurrent pregnancy loss; EGF-CFC1: Epidermal Growth Factors - Cripto/FRL-1; GEO: Gene Omnibus Expression; KEGG: Kyoto Encyclopedia of Genes and Genomes.

Decreased USP2a Expression Inhibits Trophoblast Invasion and Associates With Recurrent Miscarriage

An appropriate development of the placenta consisting of trophoblast cell migration, invasion, proliferation, and apoptosis, is essential to establishing and maintaining a successful pregnancy. Ubiquitin‐specific protease 2a (USP2a) regulates the processes of metastasis in multiple tumor cells. Yet, no known research has focused on exploring the effect of USP2a on trophoblasts and its possible mechanism in the pathogenies of recurrent miscarriage (RM). In this study, we first detected the decreased mRNA levels and the protein levels of USP2a in placental villous tissue samples from the RM patients. In vitro assays verified that overexpression of USP2a promoted human trophoblast proliferation, migration, invasion, whereas knockdown of USP2a inhibited these processes. Mechanistically, USP2a activated PI3K/Akt/GSK3β signaling pathway to promote nuclear translocation of β‐catenin and further activated epithelial-mesenchymal transition (EMT) in the trophoblasts. Moreover, transforming growth factor-beta (TGF-β) up-regulated USP2a expression in trophoblasts. Interestingly, M2 macrophage secreted TGF-β induced trophoblast migration and invasion, and an anti-TGF-β antibody alleviated this effect. Collectively, this study indicated that USP2a regulated trophoblast invasion and that abnormal USP2a expression might lead to aberrant trophoblast invasion, thus contributing to RM.

Long Noncoding RNA RP11-115N4.1 Promotes Inflammatory Responses by Interacting With HNRNPH3 and Enhancing the Transcription of HSP70 in Unexplained Recurrent Spontaneous Abortion

Background

Unexplained recurrent spontaneous abortion (URSA) is a common pregnancy complication and the etiology is unknown. URSA-associated lncRNAs are expected to be potential biomarkers for diagnosis, and might be related to the disease pathogenesis.

Objective

To investigate differential lncRNAs in peripheral blood of non-pregnant URSA patients and matched healthy control women and to explore the possible mechanism of differential lncRNAs leading to URSA.

Methods

We profiled lncRNAs expression in peripheral blood from 5 non-pregnant URSA patients and 5 matched healthy control women by lncRNA microarray analysis. Functions of URSA-associated lncRNAs were further investigated in vitro.

Results

RP11-115N4.1 was identified as the most differentially expressed lncRNA which was highly upregulated in peripheral blood of non-pregnant URSA patients (P = 3.63E-07, Fold change = 2.96), and this dysregulation was further validated in approximately 26.67% additional patients (4/15). RP11-115N4.1 expression was detected in both lymphocytes and monocytes of human peripheral blood, and in vitro overexpression of RP11-115N4.1 decreased cell proliferation in K562 cells significantly. Furthermore, heat-shock HSP70 genes (HSPA1A and HSPA1B) were found to be significantly upregulated upon RP11-115N4.1 overexpression by transcriptome analysis (HSPA1A (P = 4.39E-08, Fold change = 4.17), HSPA1B (P = 2.26E-06, Fold change = 2.99)). RNA pull down and RNA immunoprecipitation assay (RIP) analysis demonstrated that RP11-115N4.1 bound to HNRNPH3 protein directly, which in turn activate heat-shock proteins (HSP70) analyzed by protein-protein interaction and HNRNPH3 knockdown assays. Most importantly, the high expression of HSP70 was also verified in the serum of URSA patients and the supernatant of K562 cells with RP11-115N4.1 activation, and HSP70 in supernatant can exacerbate inflammatory responses in monocytes by inducing IL-6, IL-1β, and TNF-α and inhibit the migration of trophoblast cells, which might associate with URSA.

Conclusion

Our results demonstrated that the activation of RP11-115N4.1 can significantly increase the protein level of HSP70 via binding to HNRNPH3, which may modulate the immune responses and related to URSA. Moreover, RP11-115N4.1 may be a novel etiological biomarker and a new therapeutic target for URSA.

A new algorithm for the evaluation of recurrent pregnancy loss redefining unexplained miscarriage: review of current guidelines

PURPOSE OF REVIEW

Couples with recurrent pregnancy loss (RPL) are often referred to reproductive specialists to help determine the reason for their repeated losses. This review will help to develop a strategy that is effective in providing a diagnosis, efficient to administer, and cost-effective to the healthcare system.

RECENT FINDINGS

International societies have published different recommendations for the evaluation of RPL, they consider it appropriate to initiate an evaluation after two (or three) clinical miscarriages. On the contrary, the clinician who follows these guidelines will only be able to offer a possible explanation to fewer than half of the couples being evaluated. Recently, genetic testing of miscarriage tissue using 24-chromosome microarray (CMA) analysis at the time of the second pregnancy loss coupled with testing based on society guidelines has been shown provide an explanation in more than 90% of cases.

SUMMARY

New guidelines for the complete evaluation of RPL should consider adding 24-CMA testing on the miscarriage tissue. Providing couples with an explanation for recurrent loss assists them in dealing with the loss and discourages the clinician from instituting unproven therapies. Truly unexplained pregnancy loss can be reduced to less than 10% with this new algorithm. Incorporation of these strategies will result in significant cost savings to the healthcare system.

Downregulation of HDAC8 expression decreases CD163 levels and promotes the apoptosis of macrophages by activating the ERK signaling pathway in recurrent spontaneous miscarriage

Recurrent spontaneous miscarriage (RSM) is a systemic disorder that has been defined as two or more pregnancies lost before the 20th week of gestation. Although the impaired function of macrophages at the maternal-fetal interface has been reported to be associated with RSM, the underlying mechanisms have not been fully elucidated. Here, we revealed that HDAC8 plays a critical role in RSM. Our results show that the mRNA and protein expression of HDAC8 was decreased in decidual macrophages from RSM patients. Moreover, the knockdown of HDAC8 resulted in a significant decrease in CD163 expression and an increase in apoptosis in dTHP-1 macrophages. Mechanistically, the ERK signaling pathway was activated in HDAC8-knockdown macrophages. When HDAC8-knockdown cells were pretreated with the ERK inhibitor U0126, expression levels of CD163, activated caspases 3, 7 and 9, and the apoptosis rate, were rescued. Taken together, our current results suggest that HDAC8 plays an important role in macrophage activation and apoptosis and may contribute to maintaining normal pregnancy by increasing the expression of M2 marker genes and inhibiting the apoptosis of macrophages at the maternal-fetal interface.

Genetic Testing for Aneuploidy in Patients Who Have Had Multiple Miscarriages: A Review of Current Literature

Recurrent pregnancy loss (RPL) is an obstetrical complication that affects about 3% of reproductive age couples. Genetic and non-genetic causes of RPL are multiple; however, aneuploidy is the most common obstetrical complication that can explain single and recurrent pregnancy loss (present in about 60% of recognized clinical pregnancies which result in a miscarriage). Parental karyotyping will only be of potential benefit for 2 to 5 percentage of RPL couples who are translocation carriers. Products of conception (POC) karyotype analysis has been used to direct management in RPL and has been shown to be cost-effective, but the technique has many limitations including high culture failure rate and maternal cell contamination. These limitations can be significantly reduced using POC chromosomal microarray (CMA) technology. We believe that POC genetic testing should be performed after the second and subsequent pregnancy loss using CMA. Although the results will not generally alter the course of treatment, the knowledge of the reason for the loss is of great emotional comfort to many patients. In addition, POC CMA performed in conjunction with a regular complete maternal RPL work-up will identify the group of truly unexplained RPL. Thus, only 10% of patients with RPL will complete an evaluation having a euploid loss and an otherwise normal work-up. This group of "truly unexplained RPL" would be ideal for new research trials and therapies. Pre-implantation genetic testing (PGT) technology has improved recently with day 5 trophectoderm biopsy as compared to biopsy on day 3 as well as with the addition of CMA and next-generation sequencing technologies. The most recent studies on PGT-SR (PGT-Structural rearrangement) show improved clinical and live birth rates per pregnancy, as well as decreased miscarriage rate for translocation carriers. PGT-A (PGT-aneuploidy) may have a limited role in RPL in cases with documented recurrent POC aneuploidy.

Genetic analysis of products of conception. Should we abandon classic karyotyping methodology?

OBJECTIVE

To compare the results obtained by the classic and molecular methodology in the analysis of products of conception, the advantages and disadvantages of each method.

METHODS

Retrospective non-randomized analysis of results obtained from product of conception samples submitted to genetic evaluation, from 2012 to 2017. The evaluations were performed using cytogenetics and/or chromosomal microarray analysis or arrays.

RESULTS

Forty samples were analyzed using classic cytogenetics, of which 10% showed no cell growth, 50% had normal results and 40% had abnormalities. Of the 41 cases sent for array analysis it was not possible to obtain results in 7.3%, 39.5% were normal and 60.5% had abnormalities. There was no statistical difference among the results (p=0.89). Most abnormal results were seen till 9 weeks' gestation. The later abnormal miscarriage was seen at 28 weeks' gestation, with karyotype 46,XX,del(15)(q26.2-qter). The results are corroborated by the international literature.

CONCLUSION

Classic cytogenetics and array techniques showed comparable results on the type of alteration observed. Array analysis is preferable to cell culture in delayed abortions, while cytogenetics is more able to show polyploidies. Both have the same growth failure rates when product of conception tissue is not properly collected.

Genetic findings in miscarriages and their relation to the number of previous miscarriages

PURPOSE

Early pregnancy loss leads to a devastating situation for many couples. Genetic disorders found in the pregnancy tissue are a frequent cause of miscarriages. It is unclear whether maternal age or previous miscarriages are associated with a higher chromosomal anomaly rate. This study aimed to determine the cytogenetical distribution of chromosomal disorders in couples after one or more previous miscarriages as well as the influence of maternal age.

METHODS

406 fetal tissue samples obtained after spontaneous abortion between 2010 and 2014 were successfully karyotyped. This included 132 couples with at least two losses and 274 couples with sporadic miscarriage. Normal and abnormal karyotype rate was determined for age, parity, gravidity, gestational week and number of previous miscarriages by logistic regression analysis.

RESULTS

145 (35.71%) fetal tissue samples had a normal karyotype, and 261 (64.8%) did not. After adjusting for age, older patients have a statistically significantly higher probability of genetic disorders in the pregnancy tissue (p < 0.001, OR 1.064, 95% CI 1.03-1.11). With each additional year, the probability of finding chromosomal abnormalities in a miscarriage increased by 6.4%. Patients younger than 35 years have a lower probability of having chromosomal disorders in the aborted material after two or more miscarriages than after sporadic miscarriages (50.7 vs. 58.9%) (p = 0.014, OR 0.67, 95% CI 0.48-0.914). Nevertheless, the risk of embryonic chromosomal disorders in patients aged 35 and above increased from 75.5% in sporadic miscarriages to 82.4% after more than one pregnancy losses (p = 0.59, OR 1.14, 95% CI  - 0.72 to 1.92).

CONCLUSION

Chromosomal disorders found after one or more previous miscarriages are related to patients' age. Couples suffering two or more miscarriages should be further researched, especially in younger patients.

Copy number variation sequencing combined with quantitative fluorescence polymerase chain reaction in clinical application of pregnancy loss

PURPOSE

In this study, we evaluated the feasibility of the combining CNV-seq and quantitative fluorescence polymerase chain reaction (QF-PCR) for miscarriage analysis in clinical practice.

METHODS

Over a 35-month period, a total of 389 fetal specimens including 356 chorionic villi and 33 fetal muscle tissues were analyzed by CNV-seq and QF-PCR. Relationships between the risk factors (e.g., advanced maternal age, abnormal pregnancy history, and gestational age) and incidence of these chromosomal abnormalities were further analyzed by subgroup.

RESULTS

Clinically significant chromosomal abnormalities were identified in 58.95% cases. Aneuploidy was the most common abnormality (46.84%), followed by polyploidy (8.16%) and structural chromosome anomalies (3.95%). In sub-group analysis, significant differences were found in the total frequency of chromosomal abnormalities between the early abortion and the late abortion group, as well as in the distribution of chromosomal abnormalities between the advanced and the younger maternal age group. Meanwhile, the results of the logistic regression analysis identified a trend suggesting that the percentage of fetal chromosomal abnormalities is significantly higher in advanced maternal age, lesser gestational age, and lesser number of prior miscarriages.

CONCLUSION

Our study suggests that CNV-seq and QF-PCR are efficient and reliable technologies in the fetal chromosome analysis of miscarriages and could be used as a routine selection method for the genetic analysis of spontaneous abortion.