Recurrent first trimester pregnancy loss: revised definitions and novel causes

miR-126-5p protects from URSA via inhibiting Caspase-1-dependent pyroptosis of trophoblast cells

Unexplained recurrent spontaneous abortion (URSA) is a distressing pregnancy complication that seriously threat to women's reproductive health. Trophoblast pyroptosis was involved in the occurrence of URSA, but the potential mechanism remains unclear. In this work, we found CASP1 transcription and the level of pyroptosis were significantly elevated in the villous tissues of URSA patients. Suppression of cell pyroptosis by Gasdermin-D (GSDMD) or Caspase-1 inhibitors can reduce embryo resorption rate of URSA mice, while Caspase-1 over-expression in normal pregnant (NP) mice can aggravate embryo resorption. Meanwhile, a pronounced decline in the expression of microRNA-126-5p (miR-126-5p) was found in URSA patients, which was inversely related to CASP1 expression. Over-expression of miR-126-5p restrained trophoblast pyroptosis via inhibiting Caspase-1/GSDMD signaling pathway by direct binding to 3'-UTR of CASP1. Moreover, experiments in vivo substantiated that up-regulation of miR-126-5p effectively suppressed Caspase-1-mediated pyroptosis in placental tissue and significantly reduced embryo resorption rate. Collectively, these results underscored that diminished miR-126-5p expression plays a crucial role in URSA by enhancing trophoblast pyroptosis through activating Caspase-1/GSDMD signaling pathway. As a result, miR-126-5p shows significant promise as a possible biomarker for diagnosis and treatment of URSA.

Oral Cleft and Maternal History of Spontaneous Abortion: A Case-Control Study

ObjectiveTo investigate and compare the occurrence of previous spontaneous abortion among mothers of children with nonsyndromic oral clefts (NSOC) and mothers of children without NSOC; to understand if previous spontaneous abortion could be a risk factor for the occurrence of NSOC in subsequent pregnancies.DesignCase-control study.SettingNonsyndromic oral clefts is an important public health problem. In the context of investigating risk factors for the occurrence of this malformation, previous spontaneous abortion have been considered in the etiology at NSOC.ParticipantsThere were 1004 participants. In the case group 502 mothers of children with NSOC, and in the control group 502 mothers of children without NSOC or any other malformation or syndrome.InterventionsA standardized questionnaire was utilized to interview the maternal history of spontaneous abortion.Mean Outcome Measure:The data were evaluated using descriptive statistics, and comparisons were performed using the Chi-square test, adopting a significance level of 5%.ResultsThe prevalence of maternal history of spontaneous abortion was 16.3% in the case group and 15.9% in the control group. Comparing the groups there was no statistical difference (p-value = 0.93). Analyzing the occurrence of previous spontaneous abortion, separating the case group according to the type of cleft in the child, no statistical differences were observed when comparing these groups between them.ConclusionMaternal history of spontaneous abortion was not associated with NSOC, not representing an independent risk factor for NSOC in the Brazilian population.

"Unraveling the Clot-Miscarriage Nexus: Mechanisms, Management, and Future Directions in Thrombosis-Related Recurrent Pregnancy Loss"

Recurrent spontaneous abortion (RSA) is a multifactorial condition influenced by genetic, hormonal, immunological, and anatomical factors. Thrombophilia, characterized by a heightened propensity for blood clotting, is a significant contributor to RSA. This review examines the mechanisms connecting thrombosis and RSA, focusing on hypercoagulable states, placental thrombosis, inflammation, and endothelial dysfunction. Genetic and acquired thrombophilic factors, such as factor V Leiden mutation, prothrombin gene mutation, protein C and S deficiencies, antithrombin III deficiency, antiphospholipid syndrome, and hyperhomocysteinemia, are discussed in detail. The diagnosis of thrombophilia in RSA entails a comprehensive clinical evaluation, including the assessment of physical examination, medical history and laboratory investigations, although there is still debate over the need for universal screening. Therapeutic strategies, including anticoagulant and antiplatelet therapies, as well as lifestyle modifications, are tailored to individual risk factors and disease severity. Although anticoagulant therapy demonstrates potential in lowering the risk of miscarriage, additional research is necessary to refine treatment protocols and assess long-term outcomes. This review highlights the need for a nuanced approach to managing thrombophilia-associated RSA, balancing diagnostic precision with therapeutic efficacy to improve reproductive outcomes.

Male and female human papilloma virus infection and assisted reproductive technology outcomes: A comprehensive assessment from prevalence in semen to obstetric outcomes

Infertility, affecting approximately 16% of the global population, has led to increased reliance on reproductive medicine. The impact of human papillomavirus (HPV) infection in one or both partners on outcomes of Assisted Reproduction Technologies (ART) remains unclear. This prospective cohort study aimed to evaluate prevalence and effects of HPV infection in subjects and couples candidates to ART. A total of n = 510 men and n = 246 women were included and n = 145 couples (n = 290 individuals) had both partners enrolled in the study. The HPV semen infection rate was 17% (95% CI: 14-20) with HPV-42, HPV-16, HPV-53 and HPV-51 as the most frequently detected genotypes. In women, 26% (95% CI: 21-32) tested HPV-positive in cervical swabs. In 6% (95% CI: 3-11) of the couples, both partners were positive but only three couples shared the same genotypes (HPV-16; HPV-39, HPV-51, and HPV-42; HPV-31). Follicular fluids were positive in 20% (95% CI: 11-33) of samples, showing genotype discrepancies with cervical tests. Semen treatment could not completely eliminate the virus in positive samples but reduced the positivity to one-third. No significant differences in semen and embryological variables, clinical pregnancy and live birth rates, neonatal and obstetrics outcomes were observed in subjects with positivity in semen or cervix compared to respective negative groups. Cumulative live birth rates per oocyte retrieval in couples where both partners were negative or both were positive did not differ, being 37% (95% CI: 28%-47%) and 44% (95% CI: 19-73), respectively. In conclusion, HPV testing should not be considered a prerequisite for accessing ART treatments. Robust inferences for natural fertility cannot be made using our findings, as the ART setting does not fully reflect natural conditions.

Shared diagnostic genes and potential mechanisms between polycystic ovary syndrome and recurrent miscarriage revealed by integrated transcriptomics analysis and machine learning

Objective

More and more studies have found that polycystic ovary syndrome (PCOS) is significantly associated with recurrent spontaneous abortion (RSA), but the specific mechanism is not yet clear.

Methods

Based on the GEO database, we downloaded the PCOS (GSE10946, GSE6798 and GSE137684) and RSA (GSE165004, GSE26787 and GSE22490) datasets and performed differential analysis, weighted gene co-expression network (WGCNA), functional enrichment, and machine learning, respectively, on the datasets of the two diseases, Nomogram and integrated bioinformatics analysis such as immune infiltration analysis. Finally, the reliability of the diagnostic gene was verified by external verification and collection of human specimens.

Results

In this study, PCOS and RSA datasets were obtained from Gene Expression Omnibus (GEO) database, and a total of 23 shared genes were obtained by differential analysis and WGCNA analysis. GO results showed that the shared genes were mainly enriched in the functions of lipid catabolism and cell cycle transition (G1/S). DO enrichment revealed that shared genes are mainly involved in ovarian diseases, lipid metabolism disorders and psychological disorders. KEGG analysis showed significant enrichment of Regulation of lipolysis in adipocytes, Prolactin signaling pathway, FoxO signaling pathway, Hippo signaling pathway and other pathways. A diagnostic gene FAM166 B was obtained by machine learning and Nomogram screening, which mainly played an important role in Cellular component. GSEA analysis revealed that FAM166B may be involved in the development of PCOS and RSA by regulating the cell cycle, amino acid metabolism, lipid metabolism, and carbohydrate metabolism. CIBERSORT analysis showed that the high expression of FAM166 B was closely related to the imbalance of multiple immune cells. Further verification by qPCR suggested that FAM166 B could be used as a common marker of PCOS and RSA.

Conclusions

In summary, this study identified FAM166B as a common biomarker for PCOS and RSA, and conducted in-depth research and analysis of this gene, providing new data for basic experimental research and early prognosis, diagnosis and treatment of clinical diseases.

Prognostic model on pregnancy outcomes for women with recurrent spontaneous abortions treated with cyclosporin A: A single-institution experience

BACKGROUND

This study aimed to identify prognostic factors for pregnancy outcomes and construct a prognostic model for pregnancy outcomes in women with Recurrent Spontaneous Abortions (RSA) treated with cyclosporin A.

METHODS

A total of 154 RSA patients treated with cyclosporin A between October 2016 and October 2018 were retrospectively recruited. Multivariate logistic regression was applied to identify the prognostic factors for pregnancy success in RSA women treated with cyclosporin A. The Receiver Operating Characteristic (ROC) curve was applied to construct prognostic value, and the prognostic performance was assessed using area under the ROC.

RESULTS

After adjusting potential confounding factors, the authors noted increased age (OR = 0.771; 95 % CI 0.693‒0.858; p < 0.001) and positive antinuclear antibodies (OR = 0.204; 95 % CI 0.079‒0.526; p = 0.001) were associated with a reduced incidence of pregnancy success, while positive anti-β2 glycoprotein-I-antibody (OR = 21.941; 95 % CI 1.176‒409.281; p = 0.039) was associated with an increased incidence of pregnancy success after treated with cyclosporin A. The AUC of combining these variables for predicting pregnancy failure was 0.809 (95 % CI 0.735‒0.880).

CONCLUSIONS

This study systematically identified the prognostic factors for pregnancy success in women treated with cyclosporin A, and the constructed prognostic model based on these factors with relatively higher prognostic value. Further large-scale prospective studies should be performed to validate the prognostic value of the constructed model.

Adverse obstetric and perinatal outcomes of patients with history of recurrent miscarriage: a retrospective cohort study

OBJECTIVE

To examine the associations between a history of recurrent miscarriage (RM) and adverse obstetric and perinatal outcomes in the subsequent pregnancy that progressed beyond 24 weeks.

DESIGN

Retrospective cohort study.

SETTING

A large tertiary maternity hospital.

PATIENT(S)

All women who booked for antenatal care and delivery between January 2014 and August 2021 were recorded. The study was limited to women with a singleton pregnancy, and to avoid intraperson correlation, we selected the first record of delivery from each mother in the study, leaving 108,792 deliveries for analysis. Obstetric and perinatal outcomes were compared among 1994 women (1.83%) with a history of ≥2 miscarriages (RM), 11,477 women (10.55%) with a history of 1 miscarriage, and 95,321 women (87.62%) with no history of miscarriage, respectively.

INTERVENTION(S)

Women with a history of ≥2 miscarriages or RM.

MAIN OUTCOME MEASURE(S)

Obstetric complications included gestational diabetes mellitus, preeclampsia (subclassified as preterm and term preeclampsia), placenta previa, placenta accreta, and fetal distress. Perinatal outcomes included emergency cesarean section, elective cesarean section, induction, postpartum hemorrhage, preterm birth, stillbirth, Apgar score <7 at 5 minutes, neonatal asphyxia, neonatal sex, congenital; malformation, low birth weight, and neonatal death.

RESULT(S)

After adjusting for relevant confounders, there was an increased risk of adverse obstetric and perinatal outcomes in a subsequent pregnancy for women with a history of RM, specifically for placental dysfunction disorders: preterm preeclampsia (risk ratio [RR] = 1.58; 95% confidence interval [CI], 1.03-2.32), preterm birth (RR = 1.34; 95% CI, 1.15-1.54)], and abnormal placentation, that is placenta previa (RR = 1.78; 95% CI, 1.36-2.28), and placenta accreta (RR = 4.19; 95% CI, 2.75-6.13).

CONCLUSION(S)

Significant associations existed between a history of RM and the occurrence of adverse obstetric and perinatal outcomes including placental dysfunction disorders and abnormal placentation. These findings may contribute to the early detection and appropriate intervention for placenta-associated diseases in women with a history of RM, with the goal of avoiding or reducing the associated detrimental effects.

Current Status and Prospects of the Single-Cell Sequencing Technologies for Revealing the Pathogenesis of Pregnancy-Associated Disorders

Single-cell RNA sequencing (scRNA-seq) is a method that focuses on the analysis of gene expression profile in individual cells. This method has been successfully applied to answer the challenging questions of the pathogenesis of multifactorial diseases and open up new possibilities in the prognosis and prevention of reproductive diseases. In this article, we have reviewed the application of scRNA-seq to the analysis of the various cell types and their gene expression changes in normal pregnancy and pregnancy complications. The main principle, advantages, and limitations of single-cell technologies and data analysis methods are described. We discuss the possibilities of using the scRNA-seq method for solving the fundamental and applied tasks related to various pregnancy-associated disorders. Finally, we provide an overview of the scRNA-seq findings for the common pregnancy-associated conditions, such as hyperglycemia in pregnancy, recurrent pregnancy loss, preterm labor, polycystic ovary syndrome, and pre-eclampsia.

Designing Effective Multi-Target Drugs and Identifying Biomarkers in Recurrent Pregnancy Loss (RPL) Using In Vivo, In Vitro, and In Silico Approaches

Recurrent pregnancy loss (RPL) occurs in approximately 5% of women. Despite an abundance of evidence, the molecular mechanism of RPL’s pathology remains unclear. Here, we report the protective role of polo-like kinase 1 (PLK1) during RPL. We aimed to construct an RPL network utilizing GEO datasets and identified hub high-traffic genes. We also investigated whether the expressions of PLK1 were altered in the chorionic villi collected from women with RPL compared to those from healthy early pregnant women. Gene expression differences were evaluated using both pathway and gene ontology (GO) analyses. The identified genes were validated using in vivo and in vitro models. Mice with PLK1-overexpression and PLK1-knockdown in vitro models were produced by transfecting certain plasmids and si-RNA, respectively. The apoptosis in the chorionic villi, mitochondrial function, and NF-κB signaling activity was evaluated. To suppress the activation of PLK1, the PLK1 inhibitor BI2536 was administered. The HTR-8/SVneo and JEG-3 cell lines were chosen to establish an RPL model in vitro. The NF-κB signaling, Foxo signaling, PI3K/AKT, and endometrial cancer signaling pathways were identified via the RPL regulatory network. The following genes were identified: PLK1 as hub high-traffic gene and MMP2, MMP9, BAX, MFN1, MFN2, FOXO1, OPA1, COX15, BCL2, DRP1, FIS1, TRAF2, and TOP2A. Clinical samples were examined, and the results demonstrated that RPL patients had tissues with decreased PLK1 expression in comparison to women with normal pregnancies (p < 0.01). In vitro, PLK1 knockdown induced the NF-κB signaling pathway and apoptosis activation while decreasing cell invasion, migration, and proliferation (p < 0.05). Furthermore, the in vivo model proved that cell mitochondrial function and chorionic villi development are both hampered by PLK1 suppression. Our findings revealed that the PLK1/TRAF2/NF-κB axis plays a crucial role in RPL-induced chorionic villi dysfunction by regulating mitochondrial dynamics and apoptosis and might be a potential therapeutic target in the clinic.

Silencing of LncRNA SNHG6 protects trophoblast cells through regulating miR-101-3p/OTUD3 axis in unexplained recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a gestational disease with complex pathogenesis, and trophoblast cells are closely involved in the pathogenesis of RSA. This study aimed to explore the regulatory effects and mechanisms of SNHG6 on trophoblast cells. The expression of SNHG6, miR-101-3p, and OTUD3 were detected in villous tissues from patients with unexplained RSA and normal pregnant women with induced abortion by qRT-PCR. The target relationships between miR-101-3p and SNHG6/OTUD3 were confirmed by dual-luciferase reporter assay. The viability, migration, and apoptosis of trophoblast cells were measured by MTT, wound healing, and flow cytometry assays, respectively. Western blot was performed to detect the protein expression of OTUD3, Ki-67, Bax, and Bcl-2. The results showed that SNHG6 and OTUD3 were up-regulated, and miR-101-3p was down-regulated in RSA patients. MiR-101-3p was a target of SNHG6, and OTUD3 was a target of miR-101-3p. There were negative correlations between the expression of miR-101-3p and OTUD3/SNHG6 in RSA patients. In addition, both SNHG6 silencing and miR-101-3p overexpression could increase cell viability and migration, decrease cell apoptosis, up-regulate Ki-67 and Bcl-2, and down-regulate Bax in HTR-8/SVneo cells. The effects of SNHG6 silencing on HTR-8/SVneo cells were reversed by miR-101-3p silencing or OTUD3 overexpression. To sum up, silencing of SNHG6 enhanced the viability and migration, and inhibited the apoptosis of trophoblast cells through regulating miR-101-3p/OTUD3. SNHG6/miR-101-3p/OTUD3 may be potential targets for the prevention of unexplained RSA.

Multiomics Studies Investigating Recurrent Pregnancy Loss: An Effective Tool for Mechanism Exploration

Patients with recurrent pregnancy loss (RPL) account for approximately 1%-5% of women aiming to achieve childbirth. Although studies have shown that RPL is associated with failure of endometrial decidualization, placental dysfunction, and immune microenvironment disorder at the maternal-fetal interface, the exact pathogenesis remains unknown. With the development of high-throughput technology, more studies have focused on the genomics, transcriptomics, proteomics and metabolomics of RPL, and new gene mutations and new biomarkers of RPL have been discovered, providing an opportunity to explore the pathogenesis of RPL from different biological processes. Bioinformatics analyses of these differentially expressed genes, proteins and metabolites also reflect the biological pathways involved in RPL, laying a foundation for further research. In this review, we summarize the findings of omics studies investigating decidual tissue, villous tissue and blood from patients with RPL and identify some possible limitations of current studies.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Relationship Between Polymorphism of Thrombin-Activatable Fibrinolysis Inhibitor Gene +1040C/T and a Cohort of Chinese Women With Recurrent Spontaneous Abortion

The balance between coagulation and fibrinolysis is essential for a successful pregnancy. This study aimed to explore the genetic variant of +1040C/T in the coding region of thrombin-activatable fibrinolysis inhibitor (TAFI) gene in women with recurrent spontaneous abortion (RSA) and in unrelated healthy controls and to investigate the possible association between TAFI +1040C/T polymorphism and RSA. Peripheral blood samples were collected from 137 Chinese patients with RSA and 103 unrelated healthy Chinese controls. The TAFI +1040C/T polymorphism was analyzed using SNaPshot SNP typing after DNA extraction. The frequency of the C allele was lower in RSA patients compared with the controls (0.78 vs 0.84). A subanalysis of the TAFI +1040C/T polymorphism in the 2 populations of RSA women (groups 2RSA and >2RSA) showed that the +1040CT genotype was significantly higher and the +1040CC genotype was significantly lower than from that found in controls. The allele +1040C was associated with a reduced risk of RSA in both group 2RSA (OR = 0.418, 95%CI, 0.255-0.685) and group >2RSA (OR = 0.473, 95%CI, 0.274-0.819) compared with controls. Our data indicate a protective role for TAFI +1040C allele against RSA, and may be associated with the genetic susceptibility of RSA.

Predicting first-trimester outcome of embryos with cardiac activity in women with recurrent spontaneous abortion

Objective

This study was performed to evaluate the capability of routine clinical indicators to predict the early outcome of embryos with cardiac activity in women with recurrent spontaneous abortion (RSA).

Methods

A retrospective cohort study of pregnant women with a history of RSA in a Chinese tertiary hospital was performed using unadjusted and multivariable logistic regression.

Results

Of 789 pregnant women with RSA, 625 (79.21%) had ongoing pregnancy, whereas 164 (20.79%) developed abortion before 20 full weeks of gestational age even after embryonic heart motion was detected. The final model had an area under the curve of 0.81 (95% confidence interval, 0.78–0.84) with a sensitivity of 74.39%, a specificity of 76.00%, and a false-positive rate of 52.32% at a fixed detection rate of 90%.

Conclusions

The combination of multiple routine clinical indicators was valuable in predicting the early outcome of embryos with cardiac activity in viable pregnancies with RSA. However, this model might result in a high false-positive rate with a fixed detection rate of 90%; other markers must be investigated to identify first-trimester RSA once positive embryonic heart motion is established.

Women with a History of Recurrent Pregnancy Loss Are a High-Risk Population for Adverse Obstetrical Outcome: A Retrospective Cohort Study

Recurrent pregnancy loss (RPL), defined as three or more consecutive miscarriages, is hypothesized to share some of the same pathogenic factors as placenta-associated disorders. It has been hypothesized that a defect implantation causes pregnancy loss, while a partially impaired implantation may lead to late pregnancy complications. The aim of this retrospective register-based cohort study was to study the association between RPL and such disorders including pre-eclampsia, stillbirth, small for gestational age (SGA) birth, preterm birth and placental abruption. Women registered with childbirth(s) in the Swedish Medical Birth Register (MFR) were included in the cohort. Pregnancies of women diagnosed with RPL (exposed) in the National Patient Register (NPR), were compared with pregnancies of women without RPL (unexposed/reference). Obstetrical outcomes, in the first pregnancy subsequent to the diagnosis of RPL (n = 4971), were compared with outcomes in reference-pregnancies (n = 57,410). Associations between RPL and placental dysfunctional disorders were estimated by odds ratios (AORs) adjusting for confounders, with logistic regression. RPL women had an increased risk for pre-eclampsia (AOR 1.45; 95% CI; 1.24-1.69), stillbirth <37 gestational weeks (GWs) (AOR 1.92; 95% CI; 1.22-3.02), SGA birth (AOR 1.97; 95% CI; 1.42-2.74), preterm birth (AOR 1.46; 95% CI; 1.20-1.77), and placental abruption <37 GWs (AOR 2.47; 95% CI; 1.62-3.76) compared with pregnancies by women without RPL. Women with RPL had an increased risk of pregnancy complications associated with placental dysfunction. This risk population is, therefore, in need of improved antenatal surveillance.

Role of Low Molecular Weight Heparin in the Management of Unexplained Recurrent Pregnancy Loss: A Review of Literature

Recurrent pregnancy loss remains a significant challenge in gynecological practice, accounting for about 2%-4% of pregnancies. In some patients, the etiology is unknown. Unexplained recurrent pregnancy loss (URPL) refers to the spontaneous loss of three or more consecutive pregnancies without an identifiable risk factor, accounting for about 40%-50% of pregnancy losses. The review aims to understand the role of low molecular weight heparin (LMWH) in the treatment of URPL. Articles for this review have been found in the PubMed database, and studies published more than ten years before the review excluded. The articles were reviewed to determine the effect of LMWH on live birth rates, reduced late pregnancy complications, and adverse drug reactions following its use. Many studies show improved live birth rates in women treated with LMWH compared to the control, while some studies show no improvement. There was no statistically significant difference in reducing late pregnancy complications, such as preeclampsia, intrauterine growth restriction, preterm labor, and low birth weight, in either study and control groups. Adverse drug reaction was rare among women treated with LMWH and, if present, was mild and self-limiting, thus making it a safe therapy. More studies, preferably large multicenter randomized controlled trials, need to be conducted on the use of LMWH to establish a consensus guideline on the treatment of URPL.

TEAD4 ensures postimplantation development by promoting trophoblast self-renewal: An implication in early human pregnancy loss

Early pregnancy loss affects ∼15% of all implantation-confirmed human conceptions. However, evolutionarily conserved molecular mechanisms that regulate self-renewal of trophoblast progenitors and their association with early pregnancy loss are poorly understood. Here, we provide evidence that transcription factor TEAD4 ensures survival of postimplantation mouse and human embryos by controlling self-renewal and stemness of trophoblast progenitors within the placenta primordium. In an early postimplantation mouse embryo, TEAD4 is selectively expressed in trophoblast stem cell-like progenitor cells (TSPCs), and loss of Tead4 in postimplantation mouse TSPCs impairs their self-renewal, leading to embryonic lethality before embryonic day 9.0, a developmental stage equivalent to the first trimester of human gestation. Both TEAD4 and its cofactor, yes-associated protein 1 (YAP1), are specifically expressed in cytotrophoblast (CTB) progenitors of a first-trimester human placenta. We also show that a subset of unexplained recurrent pregnancy losses (idiopathic RPLs) is associated with impaired TEAD4 expression in CTB progenitors. Furthermore, by establishing idiopathic RPL patient-specific human trophoblast stem cells (RPL-TSCs), we show that loss of TEAD4 is associated with defective self-renewal in RPL-TSCs and rescue of TEAD4 expression restores their self-renewal ability. Unbiased genomics studies revealed that TEAD4 directly regulates expression of key cell cycle genes in both mouse and human TSCs and establishes a conserved transcriptional program. Our findings show that TEAD4, an effector of the Hippo signaling pathway, is essential for the establishment of pregnancy in a postimplantation mammalian embryo and indicate that impairment of the Hippo signaling pathway could be a molecular cause for early human pregnancy loss.

Factor V Leiden 1691G > A mutation and the risk of recurrent pregnancy loss (RPL): systematic review and meta-analysis

Background

Although numerous replication case-control studies have attempted to determine the association between Factor V Leiden (FVL) 1691G > A mutation and susceptibility to Recurrent pregnancy loss (RPL), there have been confliction among the results of various ethnic groups. To address this limitation, here we implemented first meta-analysis to provide with consistent conclusion of the association between FVL 1691G > A mutation and RPL risk.

Methods

After a systematic literature search, pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were used to evaluate the strength of the association. Additionally, meta-regression analyses were performed to find potential source of heterogeneity.

Results

In this meta-analysis, 62 studies, containing 10,410 cases and 9406 controls, were included in quantitative analysis. Overall population analysis revealed a significant positive association in the dominant (OR = 2.15, 95% CI = 1.84-2.50, P < 0.001), over-dominant (OR = 1.88, 95% CI = 1.61-2.19, P < 0.001), allelic (OR = 2.05, 95% CI = 1.79-2.35, P < 0.001), and heterozygote (OR = 1.97, 95% CI = 1.68-2.30, P < 0.001) models. Moreover, a significant association of dominant (OR = 3.04, 95% CI = 2.04-4.54, P < 0.001), over-dominant (OR = 2.65, 95% CI = 1.74-4.05, P < 0.001), and heterozygote (OR = 2.67, 95% CI = 1.81-4.22, P < 0.001) models was found in the Iranian population. The subgroup analysis indicated strong significant association in Asian, European, Africa population, and case-control studies but not in South Americans and cohort studies.

Conclusion

The FVL 1691G > A mutation and the risk of RPL confers a genetic contributing factor in increasing the risk of RPL, particularly in Iranians, except for South Americans.

Chromosomal copy number variations in products of conception from spontaneous abortion by next-generation sequencing technology

Fetal chromosomal abnormalities are considered to be the main cause of spontaneous abortion (SA). We aimed to determine the differences in the rates and numbers of chromosomal abnormalities between samples from women with a history of one versus more than one SA as well as between samples from first- and second-trimester SAs in women from Northeast China.In total, 1210 products of conception (POCs) from patients with a history of one or more SAs were examined. Of these 1210 samples, 434 were from women with a history of 1 SA, and 776 were from women with a history of more than 1 SA. Additionally, 1071 samples were from the first trimester, 118 were from the second trimester, and 21 were from the third trimester. We identified chromosomal abnormalities by next-generation sequencing (NGS) technology. Among the 1210 POCs in women with SA, 607 (50.17%) had fetal chromosomal abnormalities. There were no significant differences in the rates of chromosomal abnormalities according to the abortion frequency. However, first-trimester SA had a significantly higher percentage of fetal chromosomal abnormalities than second-trimester SA (P < .05). Among 663 chromosomal abnormalities, 633 abnormalities occurred in first-trimester SA; the most frequent karyotype was trisomy 16 (14.38%), followed by monosomy X (13.27%), trisomy 22 (7.90%), and trisomy 15 (5.37%). Thirty abnormalities occurred in second-trimester SA; the most frequent karyotype was trisomy 18 (26.67%), followed by monosomy X (16.67%), trisomy 21 (13.33%), and trisomy 13 (10.00%). No chromosomal abnormalities occurred in the third trimester.These findings indicate the importance of determining the genetic cause of abortion in patients with a history of SA. We also identified a trend suggesting that the percentage of fetal chromosomal abnormalities is significantly higher in first- than second-trimester SA. The detection rate of chromosomal abnormalities in POCs from SA can be increased by NGS, which is beneficial for couples with recurrent miscarriages and offers better genetic counseling in the clinical setting.

Reliability of recurrent pregnancy loss diagnosis coding in the Swedish National Patient Register: a validation study

Background: The Swedish National Patient Registry (NPR) is a nationwide registry that is used extensively for epidemiological research. Using the NPR, we recently found a recurrent pregnancy loss (RPL) incidence of 650/100,000 (0.65%) pregnant women in Sweden. It is of great importance that the quality of the coding is good and reliable in order to use NPR data for research. To specifically study RPL in Sweden, a general validation of this diagnosis in the NPR is needed. Objective: To validate the diagnosis of RPL, defined as ≥3 consecutive miscarriages before 22 gestational weeks, recorded in the NPR and assess how registered miscarriages were verified clinically (ultrasound or urine/serum hCG) by reviewing the medical records. Materials and methods: In a cohort of 6,852 women diagnosed with RPL in Sweden, during 2003-2012, a total of 238 complete medical records from 38 hospitals were reviewed. A power calculation estimated that 228 medical records had to be reviewed for a positive predictive value (PPV) of 85% (95% CI) with a power of 90%. The ICD-10 diagnoses used for RPL were N96.9 and O26.2. Results: The diagnosis of RPL was confirmed in 202 out of 238 medical records resulting in a PPV of 85% (95% CI 78-89%) out of which 59% were verified with ultrasound whereas 35% were verified only by urine/serum hCG. Conclusion: The Swedish NPR is a valuable tool for epidemiological research. We found a high PPV of RPL in the NPR, supporting the use of these data for future research.

The lncRNA CCAT2 rs6983267 G allele is associated with decreased susceptibility to recurrent miscarriage

Genetics might play various roles in susceptibility to recurrent miscarriage, and previous studies suggest that some gene polymorphisms might be associated with abortion and breast cancer onset. Colon cancer-associated transcript 2 (CCAT2) is a novel long noncoding RNA (lncRNA) transcript that might be correlated with susceptibility to multiple cancers, including breast cancer. However, whether lncRNA CCAT2 polymorphisms are related to susceptibility to recurrent miscarriage is unclear. We genotyped two lncRNA CCAT2 polymorphisms (rs6983267 and rs3843549) in 248 patients with recurrent miscarriage and 392 controls through a TaqMan real-time polymerase chain reaction assay, and the strength of each association was evaluated via 95% confidence intervals (CIs) and odds ratios (ORs). Our results showed that the rs6983267 G allele in lncRNA CCAT2 was associated with decreased susceptibility to recurrent miscarriage (TG vs. TT: adjusted OR = 0.603; 95% CI = 0.420-0.866; p = 0.0062; GG/TG vs. TT: adjusted OR = 0.620; 95% CI = 0.441-0.873; p = 0.0061). The combined analysis of the two protective polymorphisms (rs3843549 AA and rs6983267 TG/GG) revealed that individuals with two unfavorable alleles exhibited a lower risk of recurrent miscarriage than those with no or only one unfavorable allele (adjusted OR = 0.531; 95% CI = 0.382-0.739). Moreover, the decreased risk associated with the two protective alleles was most obvious in women aged less than 35 years (OR = 0.551; 95% CI = 0.378-0.8803; p = 0.0019) and in women with two to three miscarriages (adjusted OR = 0.466; 95% CI = 0.318-0.683; p < 0.0001). In conclusion, our study indicates that the rs6983267G allele might contribute to a decreased risk of recurrent miscarriage in the South Chinese population.

Correlation of single nucleotide polymorphisms in the promoter region of the ANXA5 (annexin A5) gene with recurrent miscarriages in women of Greek origin

Background: Recent findings show that a number of single nucleotide polymorphisms (SNPs) within the promoter region of the annexin A5-gene (ANXA5) reduce the expression of the reporter gene and so they display a significant association with recurrent pregnancy loss (RPL).Objective: The objective of the present study aimed to address the contribution of ANXA5 M2 haplotype consisting of four minor alleles: (SNP1: (-)467G > A, SNP2: (-)448A > C, SNP3: (-)422T > C, and SNP4: (-)373G > A) in the occurrence of recurrent pregnancy losses in the Greek population, and the role of further two minor alleles: SNP5: (-)302 T > G and SNP6: (-)1C > T as independent risk factors for RPL.Methods: A 752-bp genomic region of ANXA5 promoter was amplified by PCR using specific primers. Genotypic analysis by Sanger sequencing was performed for these six SNPs (minor alleles) in the promoter region of ANXA5 gene, in 100 (100) Greek women with recurrent miscarriages (median =3) and 70 (70) fertile controls. Statistical analysis was done using the SAS 9.3 for Windows (SAS Institute Inc, NC, USA) and SPSS packages for Windows (C.DiMaggio 2013, SAS Institute 2014).Results: This case-control study revealed that there is no significantly increased risk of RPL among the M2/ANXA5 haplotype carriers in the Greek population, as there were no statistical differences between the patients with recurrent pregnancy losses and the fertile controls (11.5% in RPL cases versus 9.29% in controls, p-value: .6364). There was no difference in SNP5 and SNP6 minor carriership between the two groups. In particular, carriers of SNP5 and SNP6 had an increased risk for RPL state with odds ratio: 1.2472 and 1.3846 respectively, however without statistically significant importance.Conclusion: The M2/ANXA5 haplotype does not differ between RPL patients and controls in the Greek population. Also, it is the first time that SNP5 and SNP6 minor alleles were evaluated extensively in women of European origin with recurrent pregnancy losses (RPL), and they do not seem to be independent risk factors in the occurrence of RPL in the Greek population. Though, this has to be confirmed in further and larger clinical trials with women of European origin.

Integrated analysis of DNA methylome and transcriptome identified CREB5 as a novel risk gene contributing to recurrent pregnancy loss

BACKGROUND

Aberrant DNA methylation is considered to be a potential cause of recurrent pregnancy loss (RPL), while potential mechanism has not yet been elucidated.

METHODS

In order to uncover the contribution of the perturbation of DNA methylation in RPL, we performed genome-wide DNA methylation analysis combined with genome-wide gene expression in decidua tissue.

FINDINGS

Totally, 539 differentially methylated regions (DMRs) were identified and significantly correlated with gene expressions. We observed that hypo-methylated DMR near CREB5 recruited transcription factors binding, such as P53 and SP1, and in turn upregulated CREB5. Compromised cell migration and apoptosis were observed in human CREB5 overexpression trophoblast cell lines, indicating dysfunctional trophoblast cells might contribute to RPL after hypo-methylation of CREB5. In addition, overexpression of CREB5 altered cell cycle.

INTERPRETATION

Our data highlights a role of CREB5 involved in the pathogenesis of RPL, and CREB5 maybe a potential diagnostic biomarker for RPL.

Subtelomeric Rearrangements in Patients with Recurrent Miscarriage

Background

The subtelomeric rearrangements are increasingly being investigated in cases of idiopathic intellectual disabilities (ID) and congenital abnormalities (CA) but are also thought to be responsible for unexplained recurrent miscarriage (RM). Such rearrangements can go unnoticed through conventional cytogenetic techniques and are undetectable even with high-resolution molecular cytogenetic techniques such as array comparative genomic hybridization (aCGH), especially when DNA of the stillbirth or families are not available. The aim of the study is to evaluate the rate of subtelomeric rearrangements in patients with RM.

Materials and Methods

In this cross-sectional study, fluorescent in situ hybridization (FISH), based on ToTelVysion telomeric probes, was undertaken for 21 clinically normal couples exhibiting a “normal” karyotype with at least two abortions. Approximately 62% had RM with a history of stillbirth or CA/ID while the other 38% had only RM.

Results

FISH detected one cryptic rearrangement between chromosomes 3q and 4p in the female partner of a couple (III:4) [46,XX,ish t(3;4)(q28-,p16+;p16-,q28+)(D3S4559+,D3S4560-,D4S3359+; D3S4560+, D4S3359- ,D4S2930+)] who presented a history of RM and family history of ID and CA. Analysis of the other family members of the woman showed that her sisters (III:6 and III:11) and brother (III:8) were also carriers of the same subtelomeric translocation t(3;4)(q28;p16).

Conclusion

We conclude that subtelomeric FISH should be undertaken in couples with RM especially those who not only have abortions but also have had at least one child with ID and/or CA, or other clinically recognizable syndromes. For balanced and cryptic anomalies, subtelomeric FISH still remains the most suitable and effective tool in characterising such chromosomal rearrangements in RM couples.

Treatment efficacy for idiopathic recurrent pregnancy loss - a systematic review and meta-analyses

INTRODUCTION

Medical treatment of women with idiopathic recurrent pregnancy loss is controversial. The objective was to assess the effects of different treatments on live birth rates and complications in women with unexplained recurrent pregnancy loss.

MATERIAL AND METHODS

We searched MEDLINE, Embase and the Cochrane Library, and identified 1415 publications. This systematic review included 21 randomized controlled trials regarding acetylsalicylic acid, low-molecular-weight heparin, progesterone, intravenous immunoglobulin or leukocyte immune therapy in women with three or more consecutive miscarriages of unknown cause. The study quality was assessed and data was extracted independently by at least two authors.

RESULTS

No significant difference in live birth rate was found when acetylsalicylic acid was compared with low-molecular-weight heparin or with placebo. Meta-analyses of low-molecular-weight heparin vs. control found no significant differences in live birth rate [risk ratio (RR) 1.47, 95% CI 0.83-2.61]. Treatment with progesterone starting in the luteal phase seemed effective in increasing live birth rate (RR 1.18, 95% CI 1.09-1.27) but not when started after conception. Intravenous immunoglobulin showed no effect on live birth rate compared with placebo (RR 1.07, 95% CI 0.91-1.26). Paternal immunization compared with autologous immunization showed a significant difference in outcome (RR 1.8, 95% CI 1.34-2.41), although the studies were small and at high risk of bias.

CONCLUSION

The literature does not allow advice on any specific treatment for idiopathic recurrent pregnancy loss, with the exception of progesterone starting from ovulation. We suggest that any treatment for recurrent pregnancy loss should be used within the context of a randomized controlled trial.

Association between thrombophilia gene polymorphisms and recurrent pregnancy loss risk in the Iranian population

Miscarriage is the most common complication in pregnancy. Considering the importance of the problem thrombophilia in pregnant women and its association with recurrent pregnancy loss (RPL), analysis of polymorphisms of genes involved in thrombophilia can be useful. We investigated the frequency and association between ten polymorphisms of seven thrombophilia genes and RPL in an Iranian population. This case-control study was conducted on 200 women with recurrent pregnancy loss and also on 200 women with at least one successful pregnancy as the control group. Using PCR-RFLP, DNA from samples were analyzed for carrying A5279G, A4070G, and FV Leiden of factor V; FXIII (Val34Leu); FII (A20210G); BF (-455 G⁄A); ITGB3 (1565T⁄C); 677C/T and 1298A/C of MTHFR; and PAI-1 (-675 I/D, 5G/4G) polymorphisms. The BF(-455 G⁄A), MTHFR (677 C⁄T, 1298A⁄ C), PAI-1 (-675 I/D,4G⁄ 5G), FV Leiden, FV (A5279G), FXIII (Val34Leu) polymorphisms, which had shown positive relation, and ITGB3 1565T⁄C were the polymorphisms with negative relation to RPL. But in this study it is indicated that there is no significant association between FII (A20210G) and FV (A4070G) polymorphism and RPL. All the data acquired from the RPL patients in this experiment illustrate the importance of screening thrombophilia. Nevertheless, more studies on large-scale populations may be needed to identify novel genetic variants.

ABBREVIATIONS

ASRM: American Society of Reproductive Medicine; HHCY: hyperhomocysteinemia; MTHFR: methylenetetrahydrofolate reductase; PCR: polymerase chain reaction; PAGE: poly-acrylamide gel electrophoresis; RPL: recurrent pregnancy loss.

Role of male genetic factors in recurrent pregnancy loss in Northeast China

OBJECTIVE

This study aimed to investigate the roles of male genetic factors, including Y chromosome microdeletions and chromosomal heteromorphism, in recurrent pregnancy loss (RPL) in Northeast China.

STUDY DESIGN

We evaluated 1072 male patients from Northeast China whose wives had a history of two or more consecutive miscarriages. We also selected 971 infertile and 200 fertile men as control groups. Semen analysis was carried out by computer-assisted sperm analysis. Y chromosome microdeletions were detected by polymerase chain reaction and chromosomes were evaluated by karyotype analysis.

RESULTS

There were no microdeletions in the RPL and fertile control groups, but 112 of the infertile men had Y chromosome microdeletions. Chromosomal heteromorphism was detected in all the groups. Patients in the infertile control group had a significantly higher percentage (2.16%) of Y variation (Yqh±) heteromorphism compared with the RPL group, but there were no significant differences in the incidences of chromosomal heteromorphism among the other groups.

CONCLUSION

Y chromosome microdeletions and chromosomal heteromorphism are not associated with RPL in Northeast China. Some RPL males had structural chromosome anomalies, all of which were reciprocal translocations. We suggest that it may not be necessary to detect Y chromosome microdeletions in RPL males with Yqh±.

Ectopic pregnancy in women with recurrent miscarriage

AIM

The aim of this study was to investigate the possible association between recurrent miscarriage (RM) and ectopic pregnancy (EP).

METHODS

In this case-control retrospective study, the clinical cards of women followed as outpatients in the RM and low-risk pregnancy offices of the Obstetrics and Gynecology Unit at the Policlinico Tor Vergata University Hospital were carefully reviewed for the occurrence of EP.

RESULTS

Overall, 598 women with RM and 2043 normal women without RM (controls) were included in the study. Among these women, 4974 pregnancies were analyzed, in which 2028 miscarriages occurred. The EP rate (3.51%) was significantly higher in RM than in control women (1.51%) [odds ratio = 2.31 (95% confidence interval: 2.3-2.4)]; it was particularly high in women with primary RM (5.11%). However, when EP rates were calculated not by women but by overall pregnancies, no differences could be found between RM and control women. In control women, the absence of a miscarriage in the reproductive history was associated with a lower rate of EP.

CONCLUSIONS

Women with RM, particularly primary RM, are at increased risk of EP. This increased risk seems to be dependent on the high number of pregnancies occurring in women with RM rather than to specific characteristics of these women.

Polymorphisms of F2, PROC, PROZ, and F13A1 Genes are Associated With Recurrent Spontaneous Abortion in Chinese Han Women

Mutations of hemostasis/coagulation-related genes have been speculated to cause recurrent spontaneous abortion (RSA). This study investigated the genetic association between the polymorphisms of factor V (F5), factor II (F2), antithrombin (SERPINC1), protein C (PROC), protein S (PROS1), protein Z (PROZ), factor XIII (F13A1), and carboxypeptidase B2 (CPB2) genes and RSA. The 426 patients with RSA and 444 controls were recruited in this study, and single-nucleotide polymorphisms (SNPs) were analyzed by using SNPscan technology. Genotype and allele frequencies of rs3136520 in F2, rs3024731 in PROZ, and rs1050782 in F13A1 showed statistically significant differences between the 2 groups. TT genotype of rs3136520 (P = .031, odds ratio [OR] = 0.986, 95% confidence interval [CI] = 0.976-0.997) and AA genotype of rs2069906 in PROC (P = .021, OR = 0.114, 95% CI = 0.014-0.902) in their recessive models and AG + GG variants of rs1050782 (P = .007, OR = 0.681, 95% CI = 0.516-0.899) in the dominant model might be associated with the reduced risk of RSA. AT + TT variants of rs3024731 (P = .010, OR = 1.479, 95% CI = 1.098-1.994) may increase disease susceptibility in dominant model. Haplotype analysis of rs3024731 and rs3024735 in PROZ displayed that the AA and TG haplotype were inclined to decrease and increase the risk of RSA, respectively. These results suggested that rs3136520, rs2069906, rs3024731, and rs1050782 may have a significant association with the genetic susceptibility of RSA in Chinese Han women.

Adverse Pregnancy Outcomes of Patients with History of First-Trimester Recurrent Spontaneous Abortion

Although a history of first-trimester recurrent spontaneous abortion (FRSA) is regarded as a risk factor in antenatal care, the characteristic of subsequent pregnancy outcome is not clearly elucidated. Here, a retrospective analysis was performed on the clinical data of 492 singleton pregnant women. 164 of them with the history of FRSA were enrolled in study group, compared to 328 deliveries without the history of FRSA. For maternal outcomes, patients in the study group delivered earlier with mean gestational age and the incidences of cesarean section and postpartum hemorrhage were higher compared to the control group. For placental outcomes, the incidence of placenta-mediated pregnancy complications (PMPC) in the study group increased in terms of late-onset preeclampsia, oligohydramnios, early-onset fetal growth restriction, and second-trimester abortion. Patients in the study group were more likely to suffer from placenta accreta, placenta increta, and placenta percreta. For perinatal outcomes, the proportion of birth defects of newborns in the study group was greater. At last, logistic regression analyses showed that the history of FRSA was an independent risk factor for cesarean section and pregnancy complications. In conclusion, women with the history of FRSA are often exposed to an elevated incidence of maternal-placental-perinatal adverse pregnancy outcomes.

Mechanistic Insight into Long Noncoding RNAs and the Placenta

Long non-coding RNAs (lncRNAs) are classified as RNAs greater than 200 nucleotides in length that do not produce a protein product. lncRNAs are expressed with cellular and temporal specificity and have been shown to play a role in many cellular events, including the regulation of gene expression, post-transcriptional modifications and epigenetic modifications. Since lncRNAs were first discovered, there has been increasing evidence that they play important roles in the development and function of most organs, including the placenta. The placenta is an essential transient organ that facilitates communication and nutrient exchange between the mother and foetus. The placenta is of foetal origin and begins to form shortly after the embryo implants into the uterine wall. The placenta relies heavily on the successful differentiation and function of trophoblast cells, including invasion as well as the formation of the maternal/foetal interface. Here, we review the current literature surrounding the involvement of lncRNAs in the development and function of trophoblasts and the human placenta.

Annexin A5 Promoter Haplotype M2 Is Not a Risk Factor for Recurrent Pregnancy Loss in Northern Europe

Introduction

Annexin A5 is an essential component of placental integrity that may potentially mediate susceptibility to phenotypes of compromised pregnancy. A promoter haplotype termed M2 of the coding gene ANXA5 has been implicated in various pregnancy complications such as preeclampsia and recurrent pregnancy loss (RPL), however with inconclusive results.

Study subjects and methods

A retrospective case-control study combining resequencing and restriction fragment length polymorphism (RFLP) analysis was undertaken in 313 women with unexplained RPL and 214 fertile women from Estonia and Denmark to estimate the RPL disease risk of the M2 haplotype in Northern Europe. Comparative prevalence of the studied ANXA5 genetic variants in human populations was estimated based on the 1000 Genomes Project (n = 675, whole-genome sequencing data) and the KORA S3 500K dataset of South German samples (n = 1644, genome-wide genotyping data).

Results

Minor allele frequency of common polymorphisms in ANXA5 promoter was up to two-fold lower among Estonian RPL subjects than fertile controls. The M2 haplotype was not associated with RPL and a trend for decreased prevalence was observed among RPL patients compared to controls both in Estonia (8.1% vs 15.2%, respectively) and Denmark (9.7% vs 12.6%). The high M2 prevalence in fertile controls was consistent with estimations for European and East Asian populations (9.6%-16.0%).

Conclusions

This study cautions to consider the M2 haplotype as a deterministic factor in early pregnancy success because: i) no RPL disease risk was associated with the haplotype in two clinically well-characterized RPL case-control study samples, ii) high prevalence of the haplotype among fertile controls and world-wide populations is inconsistent with the previously proposed severe impact on early pregnancy success, iii) weak impact of M2 haplotype on the production of ANXA5 protein has been established by others.

No evidence for mutations in NLRP7, NLRP2 or KHDC3L in women with unexplained recurrent pregnancy loss or infertility

STUDY QUESTION

Are mutations in NLRP2/7 (NACHT, LRR and PYD domains-containing protein 2/7) or KHDC3L (KH Domain Containing 3 Like) associated with recurrent pregnancy loss (RPL) or infertility?

SUMMARY ANSWER

We found no evidence for mutations in NLRP2/7 or KHDC3L in unexplained RPL or infertility.

WHAT IS KNOWN ALREADY

Mutations in NLRP7 and KHDC3L are known to cause biparental hydatidiform moles (BiHMs), a rare form of pregnancy loss. NLRP2, while not associated with the BiHM pathology, is known to cause recurrent Beckwith Weidemann Syndrome (BWS).

STUDY DESIGN, SIZE, AND DURATION

Ninety-four patients with well characterized, unexplained infertility were recruited over a 9-year period from three IVF clinics in Sweden. Blood samples from 24 patients with 3 or more consecutive miscarriages of unknown etiology were provided by the Recurrent Miscarriage Clinic at St Mary's Hospital, London, UK.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients were recruited into both cohorts following extensive clinical studies. Genomic DNA was isolated from peripheral blood and subject to Sanger sequencing of NLRP2, NLRP7 and KHDC3L. Sequence electropherograms were analyzed by Sequencher v5.0 software and variants compared with those observed in the 1000 Genomes, single nucleotide polymorphism database (dbSNP) and HapMap databases. Functional effects of non-synonymous variants were predicted using Polyphen-2 and sorting intolerant from tolerant (SIFT).

MAIN RESULTS AND THE ROLE OF CHANCE

No disease-causing mutations were identified in NLRP2, NLRP7 and KHDC3L in our cohorts of unexplained infertility and RPL.

LIMITATIONS, REASONS FOR CAUTION

Due to the limited patient size, it is difficult to conclude if the low frequency single nucleotide polymorphisms observed in the present study are causative of the phenotype. The design of the present study therefore is only capable of detecting highly penetrant mutations.

WIDER IMPLICATIONS OF THE FINDINGS

The present study supports the hypothesis that mutations in NLRP7 and KHDC3L are specific for the BiHM phenotype and do not play a role in other adverse reproductive outcomes. Furthermore, to date, mutations in NLRP2 have only been associated with the imprinting disorder BWS in offspring and there is no evidence for a role in molar pregnancies, RPL or unexplained infertility.

STUDY FUNDING/COMPETING INTERESTS

This study was funded by the following sources: Estonian Ministry of Education and Research (Grant SF0180044s09), Enterprise Estonia (Grant EU30020); Mentored Resident research project (Department of Obstetrics and Gynecology, Baylor College of Medicine); Imperial NIHR Biomedical Research Centre; Grant Number C06RR029965 from the National Center for Research Resources (NCCR; NIH). No competing interests declared.

Apolipoprotein E genotyping in women with recurrent pregnancy loss: an in silico and experimental hybrid study

The role of apolipoprotein E gene polymorphisms in the pathogenesis of recurrent pregnancy loss remains controversial. Therefore, our objective was to investigate the association between recurrent pregnancy loss and apolipoprotein E gene polymorphisms among northwest Iranian women, and also to predict the impact of these nonsynonymous single nucleotide polymorphisms on structure and function of apolipoprotein E protein. The subjects of our current study consisted of 100 women that have had two or more consecutive idiopathic first trimester miscarriages, and one hundred healthy women from the same geographical areas were used as a control group. After DNA extraction, we used a polymerase chain reaction-restriction fragment length polymorphism to genotype of the apolipoprotein E gene. In addition, we predicted the possible effects of amino acid substitutions at codons 112 and/or 158 on the structure and function of apolipoprotein E protein using Polymorphism Phenotyping online software v2. Our results showed that the rate of apolipoprotein E ε4 carriers and the frequency of the ε4 allele in the case group were statistically and significantly higher than those in the control group (P<0.05). Therefore, our data support the association of the Apo ε4 allele with RPL; however, in silico analysis predicted that the amino acid substitution at residue 112 (Apo ε4 allele) is a benign mutation. Accordingly, further studies are required to elucidate the mechanism(s) underlying the link between RPL pathogenesis and the Apo ε4 allele.

Structural genomic variation as risk factor for idiopathic recurrent miscarriage

Recurrent miscarriage (RM) is a multifactorial disorder with acknowledged genetic heritability that affects ∼3% of couples aiming at childbirth. As copy number variants (CNVs) have been shown to contribute to reproductive disease susceptibility, we aimed to describe genome-wide profile of CNVs and identify common rearrangements modulating risk to RM. Genome-wide screening of Estonian RM patients and fertile controls identified excessive cumulative burden of CNVs (5.4 and 6.1 Mb per genome) in two RM cases possibly increasing their individual disease risk. Functional profiling of all rearranged genes within RM study group revealed significant enrichment of loci related to innate immunity and immunoregulatory pathways essential for immune tolerance at fetomaternal interface. As a major finding, we report a multicopy duplication (61.6 kb) at 5p13.3 conferring increased maternal risk to RM in Estonia and Denmark (meta-analysis, n = 309/205, odds ratio = 4.82, P = 0.012). Comparison to Estonian population-based cohort (total, n = 1000) confirmed the risk for Estonian female cases (P = 7.9 × 10(-4) ). Datasets of four cohorts from the Database of Genomic Variants (total, n = 5,846 subjects) exhibited similar low duplication prevalence worldwide (0.7%-1.2%) compared to RM cases of this study (6.6%-7.5%). The CNV disrupts PDZD2 and GOLPH3 genes predominantly expressed in placenta and it may represent a novel risk factor for pregnancy complications.

Relationship between expression of COX-2, TNF-α, IL-6 and autoimmune-type recurrent miscarriage

OBJECTIVE

To investigate the roles of COX-2, TNF-α, IL-6 in the pathogenesis of autoimmune-type recurrent spontaneous abortion (RSA).

METHODS

RT-PCR was used to detect the mRNA of COX-2, TNF-α, IL-6 in the trophoblast cells of murine RSA and normal pregnant models. The COX-2, TNF-α, IL-6 protein expressions were determined by using immunohistochemisry staining method. The COX-2, TNF-α, IL-6 protein expressions were determined by ELISA.

RESULTS

The embryo loss rates in experiment group was significantly higher than that in normal pregnancy control group, the expression of COX-2, TNF-α, IL-6 in the trophoblast cells of murine RSA and normal pregnant models. The expression of COX-2 in autoimmune-type recurrent spontaneous abortion was significantly lesser than in normal pregnant models. The expression of TNF-α, IL-6 in autoimmune-type recurrent spontaneous abortion was significantly higher than in normal pregnant models. There was a positively correlation between TNF-α and IL-6. There was no relationship between COX-2, TNF-α and IL-6.

CONCLUSIONS

The abnormal expression of COX-2, TNF-α and IL-6 may result in RSA.

Paternal factor V Leiden and recurrent pregnancy loss: a new concept behind fetal genetics?

BACKGROUND

In up to 50% of couples affected by recurrent pregnancy loss, no identifiable cause is established. Fetal and maternal factors may be equally important in the establishment and maintenance of the placental/maternal arteriovenous anastomoses. Therefore,the inheritance of thrombophilia-related genes may be an important factor in the pathophysiology of recurrent pregnancy loss. Most of the research on recurrent pregnancy loss and thrombophilia has focused on maternal factors, but little is known about the paternal contribution.

OBJECTIVES

On that basis, we studied the association between inherited paternal thrombophilias and recurrent pregnancy loss in a narrowly selective group of 42 Argentine males from couples that presented without any known risk factors for recurrent pregnancy loss.

PATIENTS AND METHODS

The genotypic distributions of factor (F) V Leiden and prothrombin G20210A among cases were compared with those from a reference group composed of 200 Argentine men.

RESULTS

We found a significant difference in the distribution of FV Leiden between both groups (16.7% vs. 3.0%), but no difference was found in the distribution of prothrombin G20210A (2.4% vs.2.0%). Those couples with paternal FV Leiden carriage would be six times more likely to experience recurrent pregnancy loss despite no other apparent cause (OR = 6.47; 95% CI, 2.06–20.39).

CONCLUSION

We found evidence of an association between the paternal carriage of FV Leiden and the predisposition to recurrent pregnancy loss, thereby supporting the hypothesis that genetic contributions from both parents are essential factors in the development of this obstetric disorder.

A novel association between cytotoxin-associated gene A (CagA) positive strain of Helicobacter pylori and unexplained recurrent early pregnancy loss

OBJECTIVE

To assess whether or not there is an association between the cytotoxin-associated gene A (CagA)-positive strain of Helicobacter (H.) pylori and unexplained recurrent early pregnancy loss (REPL).

METHODS

A case control study was conducted in a tertiary care maternity centre during a one-year period. Ninety-six women with first trimester unexplained REPL admitted for surgical or medical termination of pregnancy were included in the study group (group 1), along with 96 women who suffered a first trimester missed abortion but had no history of REPL and who were included in the control group (group 2). Sera from all these women were collected for detection of the CagA line of IgG type of H. pylori using an immunoblotting assay. The main outcome measure was the association between the CagA-positive strain of H. pylori and unexplained REPL.

RESULTS

A significantly greater proportion of women were seropositive for the CagA- H. pylori strain in group 1 than in group 2 (71 [74%] vs. 51 [53%], respectively; p = 0.003).

CONCLUSION

The CagA-positive strain of H. pylori seems to be significantly more prevalent among women with unexplained REPL when compared to women with a single missed abortion.