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].

Sperm DNA fragmentation and idiopathic recurrent pregnancy loss: Results from a multicenter case-control study

BACKGROUND

Sperm DNA fragmentation was hypothesized to have a role in the pathogenesis of recurrent pregnancy loss. Unfortunately, the quality of already published evidence is low.

OBJECTIVES

To investigate the association between sperm DNA fragmentation and idiopathic recurrent pregnancy loss by limiting, as much as possible, the interference of confounding factors.

MATERIALS AND METHODS

This was a retrospective multicenter case-control study conducted in two Italian University Hospitals (i.e., Policlinico Gemelli, Rome and Humanitas S. Pio X, Milan) from July 2020 to March 2022. Cases were men belonging to couples affected by first trimester idiopathic recurrent pregnancy loss, defined as the previous loss of two or more pregnancies. Two control groups were selected: (i) men belonging to couples with proven fertility (i.e., at least two previous full-term pregnancies) (control group A); (ii) men belonging to couples with proven infertility (i.e., the failure to achieve a pregnancy after 12 months or more of regular unprotected sexual intercourse) (control group B). The sperm DNA fragmentation index was measured by the terminal deoxynucleotidyl transferase dUTP nick end labeling assay.

RESULTS

We included 74 cases, 37 men with proven fertility (control group A) and 100 men belonging to infertile couples (control group B). The median sperm DNA fragmentation index was significantly lower in control group A (17%, interquartile range: 14.3%-20.6%) compared to both case group (24.5%, interquartile range: 17%-32%; p < 0.0001) and control group B (24%, interquartile range: 18.9%-30%; p = 0.001). The rate of subjects with sperm DNA fragmentation index greater than 30% was significantly higher in both case groups (28%, 95% confidence interval [18%-40%]) and control group B (26%, 95% confidence interval [18%, 36%]) compared to control group A (0%, 95% confidence interval [0%-10%]) (p < 0.001). Multivariate regression models yielded a significant association between sperm DNA fragmentation index and recurrent pregnancy loss (adjusted odds ratio 1.13, 95% confidence interval [1.04-1.23], p = 0.006), but failed to show an association between sperm DNA fragmentation index and infertility (adjusted odds ratio 1.13, 95% CI [1-1.29], p = 0.05).

CONCLUSIONS

Men within couples affected by recurrent pregnancy loss or infertility had a significantly higher rate of sperm DNA fragmentation compared to fertile controls. However, after adjusting for covariates, sperm DNA fragmentation index was associated only with recurrent pregnancy loss.

Dysregulated miRNAs in recurrent miscarriage: A systematic review

Recurrent miscarriage (RM) is a complex reproductive medicine disease that affects many families. The cause of RM is unclear at this time; however, lifestyle and genetic variables may influence the process. The slight alteration in miRNA expression has enormous consequences for a variety of difficulties, one of which may be RM. The target of this systematic study was to provide a framework of the dysregulated miRNAs in RM. The Prisma guidelines were applied to perform current systematic review pertaining to articles in the seven databases. Thirty-nine papers out of 245 received fulfilled all inclusion requirements. From all the mentioned miRNAs, 40 were up-regulated (65.57 %), whereas 21 were down-regulated (34.43 %). These dysregulated miRNAs contributed to the pathophysiology of RM by influencing key pathways and processes such as apoptosis, angiogenesis, epithelial-mesenchymal transition, and the immune system. Understanding the dysregulation of miRNAs, as well as the pathways and processes that engage these miRNAs and impact disease pathogenesis, may aid in clarifying the unknown underlying mechanisms of RM and the development of novel molecular therapeutic targets and medical domains.

Correlation of TGF-β signaling pathway gene polymorphisms with unexplained recurrent spontaneous abortion

BACKGROUND

The association of key genes in the transforming growth factor-β (TGF-β) signaling pathway and their gene polymorphisms with unexplained recurrent spontaneous abortion (URSA) is unclear.

OBJECTIVE

To investigate the association of gene polymorphisms related to the TGF-β signaling pathway in URSA women.

METHODS

The study population consisted of 80 women with URSA and 90 normal control women, of which 10 women with URSA and 10 normal control women underwent high-throughput sequencing to select loci, and the remaining 70 women with URSA and 80 normal control women underwent flight mass spectrometry experiments to verify gene loci polymorphism. A total of 7 polymorphic loci in interleukin-6 (IL-6), TGF-β1, TNF-α, SMAD1, and TNFRSF4 genes were screened by high-throughput sequencing combined with a review of databases. An SNP flight mass spectrometer (Mass ARRAY detection system) was applied to detect the polymorphisms and their frequencies in 70 women with URSA and 80 normal control women at the 7 gene loci.

RESULTS

Among the 7 loci of IL-6, TGF-β1, TNF-α, SMAD1, and TNFRSF4 genes, 2 loci were found to have significantly different allele and genotype frequency distributions between the 70 URSA and 80 normal controls, one was the IL-6 gene -174G/C locus (rs1800795), the risk of disease was 2.636 and 3.231 times higher in individuals carrying the C allele and CC genotype than in those carrying the G allele and GG genotype, respectively; the other was the TGF-β1 gene -509T/C locus (rs1800469), and the risk of disease was 1.959 and 3.609 times higher in individuals carrying the T allele and TT genotype than in those carrying the C allele and CC genotype, respectively. The remaining 5 genetic loci have no statistically significant.

CONCLUSION

IL-6 gene -174G/C locus (rs1800795) genotype CC and allele C may be the causative factor of URSA, TGF-β1 gene -509T/C locus (rs1800469) genotype TT and allele T may be the causative factor of URSA, and polymorphisms of the 2 loci may be associated with URSA.

Analysis of copy number variations and possible candidate genes in spontaneous abortion by copy number variation sequencing

Introduction

Embryonic chromosomal abnormalities represent a major causative factor in early pregnancy loss, highlighting the importance of understanding their role in spontaneous abortion. This study investigates the potential correlation between chromosomal abnormalities and spontaneous abortion using copy number variation sequencing (CNV-seq), a Next-Generation Sequencing (NGS) technology.

Methods

We analyzed Copy Number Variations (CNVs) in 395 aborted fetal specimens from spontaneous abortion patients by CNV-seq. And collected correlated data, including maternal age, gestational week, and Body Mass Index (BMI), and analyzed their relationship with the CNVs.

Results

Out of the 395 cases, 67.09% of the fetuses had chromosomal abnormalities, including numerical abnormalities, structural abnormalities, and mosaicisms. Maternal age was found to be an important risk factor for fetal chromosomal abnormalities, with the proportion of autosomal trisomy in abnormal karyotypes increasing with maternal age, while polyploidy decreased. The proportion of abnormal karyotypes with mosaic decreased as gestational age increased, while the frequency of polyploidy and sex chromosome monosomy increased. Gene enrichment analysis identified potential miscarriage candidate genes and functions, as well as pathogenic genes and pathways associated with unexplained miscarriage among women aged below or over 35 years old. Based on our study, it can be inferred that there is an association between BMI values and the risk of recurrent miscarriage caused by chromosomal abnormalities.

Discussion

Overall, these findings provide important insights into the understanding of spontaneous abortion and have implications for the development of personalized interventions for patients with abnormal karyotypes.

Bioinformatics analysis of competing endogenous RNA network in decidual natural killer cell from unexplained recurrent spontaneous abortion

BACKGROUND

Decidual natural killer (dNK) cell plays a pivotal role in maintaining pregnancy, especially in the first trimester. Noncoding-RNAs (ncRNAs) are critical regulators of transcription and protein expression. Dysregulation of ncRNAs may be involved in the pathogenesis of unexplained recurrent spontaneous abortion (URSA). However, the role of competing endogenous RNA (ceRNA) based on mRNA-miRNA-lncRNA network in regulating the incidence and progression of URSA remains elusive. The aim of the study is to identify the regulatory network of mRNA-miRNA-LncRNA ceRNA based on bioinformatics analysis in dNK from patients with URSA.

METHODS

Eligible studies were retrieved from PubMed, Embase, and the Gene Expression Omnibus (GEO) databases to identify differentially expressed genes (DEGs), miRNAs and LncRNAs in dNK cells of patients with URSA. Protein-protein interaction (PPI) network was constructed by STRING database and Cytoscape software. Potential regulatory miRNAs and lncRNAs of mRNAs were predicted by miRTarBase and RNA22 and subject to bioinformatics analysis.

RESULTS

A total of 634 DEGs were screened, including 290 upregulated and 344 downregulated DEGs. Among 207 differentially expressed lncRNAs, 110 lncRNAs were upregulated and 97 were downregulated. According to node degree, 30 hub genes were identified for subsequent research. After drawing the Venn diagram and matching to Cytoscape, an mRNA-miRNA-lncRNA network linked to the pathogenesis of URSA in dNK cells was constructed.

CONCLUSIONS

A novel regulatory network of mRNA-miRNA-lncRNA ceRNA is established in dNK cells from patients with URSA. All RNAs might be used as the biomarkers of the pathogenesis of URSA.

Hereditary chromosomal 9 inversion (p22q13) 9 as a cause for recurrent pregnancy loss: a case report

BACKGROUND

Chromosomal aberrations are as common as 13.8% in the infertile population. The incidence of pericentric inversion of chromosome 9 is approximately 1-3%. However, although these inversions do not alternate phenotype, there have been conflicting data about their effect as they were correlated with infertility, recurrent pregnancy loss, and deceased children, with no clear evidence of the inversions being the causative factor for these events.

CASE PRESENTATION

We report a case report of an Arab family with many members with inv(9)(p22q13). Our proband male aged 35 years at time of presentation with primary infertility. Some members, such as a brother aged 34 years, who had this inversion suffered from recurrent pregnancy loss while other members of similar reproductive age did not.

CONCLUSIONS

inv(9)(p22q13) might be a hereditary anomaly that might be a risk factor for recurrent pregnancy loss in its members.

Investigating the Association of MTHFR C677T Gene Polymorphism with Recurrent Spontaneous Abortion Among Azerbaijani Women from Northwest Iran

Background: Recurrent spontaneous abortion (RSA), defined as two or more succeeding abortions during 20 weeks of gestation, affects 3-5% of pregnancies. Several studies have found that most women with RSA had at least one (and sometimes two copies) of the methylenetetrahydrofolate reductase (MTHFR) C677T variant. Materials and Methods: The study involved 118 women who had two or more spontaneous abortions (SAs) as the case group and 118 women who had at least one live birth but no SA as the control group. Clinical features such as age, body mass index (BMI), medication received, family history of abortion, and thrombophilia were investigated. Real-time PCR was used for genotyping subjects for MTHFR C677T gene polymorphism. Results: Significant differences in age, BMI, and medication received characters have been shown between those in the patients' group. For the MTHFR C677T gene, the genotypes for the patients' group were 36%, 60%, and 4%, whereas the genotypes for the control group were 30%, 58%, and 12%. In addition, the C and T allelic frequencies were 59% and 41% in the healthy control group and 67% and 33% in the patients' group, respectively. A significant association was found between the TT genotype and RSA. A 3.84-fold increased risk of RSA was associated with the TT genotype (odds ratio = 3.84, confidence interval: 1.28-10.93, p-value = 0.02). Conclusions: In this study, homozygosity for the T allele was significantly lower in the RSA-affected than in healthy women, whereas heterozygosity did not vary substantially between the two groups, which was in line with other studies.

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.

Association of IL-17 and IL-27 polymorphisms with susceptibility to recurrent pregnancy loss and pre-eclampsia: A systematic review and meta-analysis

OBJECTIVE

Recurrent pregnancy loss (RPL) and pre-eclampsia (PE) are immune-related pregnancy complications that have been linked to CD4+ T cells and their cytokines, which can be influenced by genetic polymorphisms. This meta-analysis aimed to investigate the relationship between interleukin (IL)-17 and -27 polymorphisms and the susceptibility to RPL and PE.

METHODS

All eligible case-control studies published up to February 2023 were identified by searching PubMed, EMBASE, Cochrane, Web of Science, and Google Scholar. The risk of recurrent pregnancy loss and PE associated with the IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were estimated for each study.

RESULTS

The meta-analysis incorporated a total of 13 studies. The overall analysis indicated that IL-17 rs2275913, IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with immune-related pregnancy complications, including RPL and PE. However, when the analysis was stratified by disease type, the IL-17 rs2275913 polymorphism was found to be associated with an increased risk of RPL (recessive model AA/GA + GG: OR = 1.68, 95% confidence interval [CI]: 1.13-2.49, p = .01).

CONCLUSIONS

The IL-17 rs763780, IL-27 rs153109, and IL-27 rs17855750 polymorphisms were not significantly associated with RPL and PE, whereas the IL-17 rs2275913 polymorphism was associated with the susceptibility to recurrent miscarriage.

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

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

Proteomic profiling analysis of human endometrium in women with unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) seriously affects female reproductive health, causing a great burden to patients both physically and mentally. Endometrial decidualization plays an important role in pregnancy, and impaired decidualization is an essential cause of URSA, but the cause of the damage is still poorly understood. This study aimed to reveal the pathogenesis of URSA by analyzing the differential protein expression profiles in the decidual tissue of patients with recurrent abortion compared to those with normal pregnancy. Morphological analysis revealed abnormal decidualization of endometrial tissue in patients with URSA. Quantitative proteomics analysis showed that a total of 146 differentially expressed proteins were identified between the two groups, among which 95 proteins were downregulated and 51 proteins were upregulated. Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways revealed that the protein expression profile and signaling pathways of endometrium in patients with URSA changed significantly, and cytoskeleton remodeling and morphological transformation disorders were associated with abortion induced by incomplete decidualization. Meanwhile, transcription factors analysis showed that the 3 most affected families were zf-C2H2, MYB and HMG. Therefore, our study may provide a basis for searching for potential markers of decidualization injury. SIGNIFICANCE: At present, there are still about 50% of RSA patients with unknown causes, which brings great difficulties and blindness to clinical diagnosis and treatment.The limited proteomic studies on URSA further contribute to the lack of understanding in this field. However, in this study, the focus was on proteomic profiling analysis of the human endometrium in URSA patients compared to normal women. The findings revealed that cytoskeletal remodeling disorder is a significant contributor to the failure of decidualization in URSA patients. This insight highlights the potential role of cytoskeleton-related proteins in the pathogenesis of URSA, providing valuable information for further research and potential therapeutic interventions.

miR604A>G gene polymorphism is associated with recurrent pregnancy loss in Turkish women

OBJECTIVE

Recurrent pregnancy loss is considerably a reproductive health problem for couples. Genetic, epigenetic, and environmental factors play an important role in the development of recurrent pregnancy loss. While there are many causes, genetic and epigenetic factors are common. In this study, we aimed to examine the association between miR604 (rs2368393) A>G gene polymorphism and the risk of recurrent miscarriage in the Turkish population.

METHODS

The study included 250 participants (i.e., 150 patients and 100 controls). DNA samples were isolated from peripheral blood, and polymerase chain reactions and restriction fragment length polymorphism methodologies were applied.

RESULTS

The genotype distribution and allele frequencies of miR604A>G gene showed statistically significant differences between patients and control groups (p=0.002 and p<0.002, respectively).

CONCLUSION

As a result of the study, we found that the AA genotype and A allele of the miR604A>G gene were statistically significant for the risk of recurrent pregnancy loss in Turkish women.

Microarray profiling of serum micro-RNAs in women with Chlamydia trachomatis-associated recurrent spontaneous abortion: A case control study

Chlamydia trachomatis infection is a major cause of sexually transmitted diseases and adverse pregnancy outcomes such as recurrent spontaneous abortion (RSA). Micro-RNAs (miRNAs) have been known to be upregulated/downregulated in various reproductive-associated diseases such as ectopic pregnancy, preterm birth and pre-eclampsia. However, there is paucity of literature on miRNA profile in C. trachomatis-infected RSA. The present study aimed to determine the profile of serum miRNAs followed by their validation in C. trachomatis-infected RSA and to find target genes involved in biological pathways. Non-heparinized blood and first void urine were collected from 30 non-pregnant women with RSA and 30 non-pregnant women with ≥2 successful deliveries (controls) attending Department of Obstetrics and Gynaecology, Safdarjung hospital, New Delhi, India. C. trachomatis detection was done in urine by PCR and chlamydial load was determined by quantitative real-time PCR (qRT-PCR). miRNA expression was studied by microarray analysis followed by in vitro validation by qRT-PCR. Analysis of target genes/pathways was characterized in silico. 06 RSA patients were infected with C. trachomatis, while chlamydial load was found to be 6000-12,000 copies/ml. 110 circulating miRNAs were expressed differentially in infected RSA patients compared with controls. Of these, 16 were overexpressed and 94 downregulated. 06 differentially expressed circulating miRNAs were selected to validate the microarray results. qRT-PCR data confirmed the reliability of the microarray results: miR-4443, -5100, -7975 showed statistically significant upregulation, while miR-6808-5p, -3148, -6727-5p were significantly downregulated in infected RSA patients versus controls. Chlamydial load was positively correlated with these upregulated miRNAs. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that target genes of miRNAs in RSA are involved in AMPK, Akt and mTOR signaling pathways. Overall results indicate that differentially expressed circulating miRNAs are involved in pathogenesis of C. trachomatis-associated RSA and have the potential to be used as biomarkers for predicting RSA.

The crucial role of titin in fetal development: recurrent miscarriages and bone, heart and muscle anomalies characterise the severe end of titinopathies spectrum

BACKGROUND

Titin truncating variants (TTNtvs) have been associated with several forms of myopathies and/or cardiomyopathies. In homozygosity or in compound heterozygosity, they cause a wide spectrum of recessive phenotypes with a congenital or childhood onset. Most recessive phenotypes showing a congenital or childhood onset have been described in subjects carrying biallelic TTNtv in specific exons. Often karyotype or chromosomal microarray analyses are the only tests performed when prenatal anomalies are identified. Thereby, many cases caused by TTN defects might be missed in the diagnostic evaluations. In this study, we aimed to dissect the most severe end of the titinopathies spectrum.

METHODS

We performed a retrospective study analysing an international cohort of 93 published and 10 unpublished cases carrying biallelic TTNtv.

RESULTS

We identified recurrent clinical features showing a significant correlation with the genotype, including fetal akinesia (up to 62%), arthrogryposis (up to 85%), facial dysmorphisms (up to 73%), joint (up to 17%), bone (up to 22%) and heart anomalies (up to 27%) resembling complex, syndromic phenotypes.

CONCLUSION

We suggest TTN to be carefully evaluated in any diagnostic process involving patients with these prenatal signs. This step will be essential to improve diagnostic performance, expand our knowledge and optimise prenatal genetic counselling.

Maternal candidate gene variants, epigenetic factors, and susceptibility to idiopathic recurrent pregnancy loss: A systematic review

BACKGROUND

Recurrent pregnancy loss is defined as the loss of two or more pregnancies and is a distressing condition for couples.

OBJECTIVE

To investigate the relationship between variants in the candidate susceptibility genes and epigenetic factors to identify risk factors for idiopathic recurrent pregnancy loss (iRPL).

SEARCH STRATEGY

A systematic literature search was performed using PubMed, Google Scholar, ScienceDirect, and Scopus databases. Insilico analysis was carried out using ShinyGO and STRING software.

SELECTION CRITERIA

Research papers examining the association between variations in genetic and epigenetic factors and iRPL.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two authors.

MAIN RESULTS

In total, 83 research papers were finally selected for the present study. Among all the genes involved in the pathogenesis of recurrent pregnancy loss, polymorphisms in IL superfamily genes, VEGF, ESR, and MTHFR were the most investigated.

CONCLUSION

Polymorphisms in angiogenesis, immune tolerance, and thrombophilia pathway genes, which occur independently or synergistically, may lead to various complications during fetal development. Identification of multi-allele risk variants and epigenetic factors in women will be helpful in the identification of high-risk pregnancies.

PROSPERO REGISTRATION NUMBER

Prospero CRD42021287315.

Alpha-enolase 1 knockdown facilitates the proliferation and invasion of villous trophoblasts by upregulating COX-2

BACKGROUND

Enolase 1 (ENO1) is a metabolic enzyme which participates in pyruvate synthesis and ATP production in cells. Previously, differential expression of ENO1 was discovered in villous tissues between recurrent miscarriage and induced abortion. This study was designed to explore whether ENO1 influences the proliferation and invasion of villous trophoblasts and the related molecular mechanisms.

METHODS

First, ENO1 expression in placental villus tissues collected from recurrent miscarriage (RM) patients and women for induced abortion as well as in trophoblast-derived cell lines was detected by RT-qPCR and western blotting. ENO1 localization and expression in villus tissues were further confirmed through immunohistochemistry staining. Then, the effects of ENO1 downregulation on trophoblast Bewo cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) process were evaluated by CCK-8 assay, transwell assay, and western blotting. As for the regulatory mechanism of ENO1, the expression of COX-2, c-Myc and cyclin D1 in Bewo cells after ENO1 knockdown was finally evaluated by RT-qPCR and western blotting.

RESULTS

ENO1 was mainly localized in the cytoplasm, with very small amounts in the nucleus of trophoblast cells. ENO1 expression in the villi tissues of RM patients was significantly increased, when compared with the villous tissues of healthy controls. Furthermore, Bewo cells, a trophoblast cell line with relatively higher expression of ENO1, was used to downregulate the ENO1 expression by ENO1-siRNA transfection. ENO1 knockdown significantly facilitated Bewo cell growth, EMT process, migration, and invasion. ENO1 silencing markedly elevated COX-2, c-Myc, and cyclin D1 expression.

CONCLUSION

ENO1 may participate in the development of RM via suppressing the growth and invasion of villous trophoblasts via reducing the expression of COX-2, c-Myc, and cyclin D1.

Identification and verification of diagnostic biomarkers in recurrent pregnancy loss via machine learning algorithm and WGCNA

Background

Recurrent pregnancy loss defined as the occurrence of two or more pregnancy losses before 20-24 weeks of gestation, is a prevalent and significant pathological condition that impacts human reproductive health. However, the underlying mechanism of RPL remains unclear. This study aimed to investigate the biomarkers and molecular mechanisms associated with RPL and explore novel treatment strategies for clinical applications.

Methods

The GEO database was utilized to retrieve the RPL gene expression profile GSE165004. This profile underwent differential expression analysis, WGCNA, functional enrichment, and subsequent analysis of RPL gene expression using LASSO regression, SVM-RFE, and RandomForest algorithms for hub gene screening. ANN model were constructed to assess the performance of hub genes in the dataset. The expression of hub genes in both the RPL and control group samples was validated using RT-qPCR. The immune cell infiltration level of RPL was assessed using CIBERSORT. Additionally, pan-cancer analysis was conducted using Sangerbox, and small-molecule drug screening was performed using CMap.

Results

A total of 352 DEGs were identified, including 198 up-regulated genes and 154 down-regulated genes. Enrichment analysis indicated that the DEGs were primarily associated with Fc gamma R-mediated phagocytosis, the Fc epsilon RI signaling pathway, and various metabolism-related pathways. The turquoise module, which showed the highest relevance to clinical symptoms based on WGCNA results, contained 104 DEGs. Three hub genes, WBP11, ACTR2, and NCSTN, were identified using machine learning algorithms. ROC curves demonstrated a strong diagnostic value when the three hub genes were combined. RT-qPCR confirmed the low expression of WBP11 and ACTR2 in RPL, whereas NCSTN exhibited high expression. The immune cell infiltration analysis results indicated an imbalance of macrophages in RPL. Meanwhile, these three hub genes exhibited aberrant expression in multiple malignancies and were associated with a poor prognosis. Furthermore, we identified several small-molecule drugs.

Conclusion

This study identifies and validates hub genes in RPL, which may lead to significant advancements in understanding the molecular mechanisms and treatment strategies for this condition.

Immune Checkpoints in Recurrent Pregnancy Loss: New Insights into a Detrimental and Elusive Disorder

Recurrent pregnancy loss (RPL) refers to two or more miscarriages before 20 weeks gestation. Its prevalence is 1-2%; its pathogenesis remains unexplained in more than 50% of cases, in which the cause is thought to be abnormal immune activity during placentation leading to a lack of pregnancy-induced immune tolerance. It is unknown whether immune activity is deranged in the endometrium of women with RPL. We studied the gene expression and the quantitative tissue protein levels of three immune checkpoints (CD276, which enhances cytotoxic T-cell activity, cytotoxic T-lymphocyte-associated antigen-4 [CTL-4], which reduces Th1 cytokine production, and lymphocyte activation gene-3 [LAG-3], which shows suppressive activity on Tregs and CD4+ T-cells) in endometrial samples from 27 women with unexplained RPL and in 29 women with dysfunctional uterine bleeding and previous uneventful pregnancies as controls. RNA isolation, real-time PCR, protein isolation, and ELISA were performed. CD276 gene expression and protein tissue levels were significantly lower in the endometrium of the RPL group than in the controls, whereas both CTL-4 and LAG-3 were significantly higher. This difference suggests defective endometrial immune regulation and overactivation of immune response in women with a history of RPL, at least in relation to controls with dysfunctional uterine bleeding and previous normal reproductive history.

Endogenous retrotransposons cause catastrophic deoxyribonucleic acid damage in human trophoblasts

OBJECTIVE

To determine the mechanistic role of mobile genetic elements in causing widespread DNA damage in primary human trophoblasts.

DESIGN

Experimental ex vivo study.

SETTING

Hospital-affiliated University.

PATIENT(S)

Trophoblasts from a patient with unexplained recurrent pregnancy loss and patients with spontaneous and elective abortions (n = 10).

INTERVENTION(S)

Biochemical and genetic analysis and modification of primary human trophoblasts.

MAIN OUTCOME MEASURE(S)

To phenotype and systematically evaluate the underlying pathogenic mechanism for elevated DNA damage observed in trophoblasts derived from a patient with unexplained recurrent pregnancy loss, transcervical embryoscopy, G-band karyotyping, RNA sequencing, quantitative polymerase chain reaction, immunoblotting, biochemical and siRNA assays, and whole-genome sequencing were performed.

RESULT(S)

Transcervical embryoscopy revealed a severely dysmorphic embryo that was euploid on G-band karyotyping. RNA sequencing was notable for markedly elevated LINE-1 expression, confirmed with quantitative polymerase chain reaction, and that resulted in elevated expression of LINE-1-encoded proteins, as shown by immunoblotting. Immunofluorescence, biochemical and genetic approaches demonstrated that overexpression of LINE-1 caused reversible widespread genomic damage and apoptosis.

CONCLUSION(S)

Derepression of LINE-1 elements in early trophoblasts results in reversible but widespread DNA damage.

Crosstalk between Placental Trophoblast and Decidual Immune Cells in Recurrent Miscarriage

Recurrent miscarriage (RM) is a pregnancy complication associated with dysregulation of the maternal-fetal interface. We aimed to identify dysfunctional interactions between trophoblast cells and decidual immune cells in RM. We downloaded single-cell RNA sequencing (scRNA-seq) datasets (GSE214607) from the Gene Expression Omnibus (GEO) datasets for further analysis using the R software. The data comprised of paired placental and decidual tissues, including those from patients diagnosed with RM and matched healthy controls. A total of 22976 cells were identified in 11 cell types, including trophoblasts, immune cells, and other cells. We divided trophoblast cells into three types and analyzed their interactions with decidual immune cells. Additionally, we re-clustered NK&T cells and macrophages, identified differentially expressed genes (DEGs), enriched their functions, and compared the cell interactions with trophoblast cells in each cell type. Our single-cell atlas of the maternal-fetal interface revealed alterations in the cellular organization of the decidua and placenta, cell type-specific transcriptome, and cell communication between immune and non-immune cells in RM, which are critical for illuminating the pathophysiology of RM.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss

BACKGROUND

Although the importance of miRNA variants in female reproductive disorders has been frequently reported, the association between miRNA polymorphisms and recurrent pregnancy loss (RPL) has been poorly studied. In this study, we aimed to assess the correlation of four different miRNA variants to unexplained RPL.

METHODS AND RESULTS

The prevalence of four SNPs including miR-21 rs1292037, miR-155-5p rs767649, miR-218-2 rs11134527, and miR-605 rs2043556 in 280 cases with iRPL and 280 controls was performed. The DNA was extracted from all subjects and the SNPs were genotyped using RFLP-PCR methods. The data revealed that rs1292037 and rs767649 were significantly associated with higher rates of iRPL in patients compared with controls while rs11134527 and rs2043556 showed no association with increased rates of iRPL among patients. The haplotypes T-A-G-G and T-A-G-A were the most frequent in both cases and controls. Three haplotypes including T-T-G-A, C-T-G-G, and T-A-A-A showed significantly different frequencies in patients in comparison to healthy females.

CONCLUSION

This study suggests that rs1292037 and rs767649 could be risk factors for increased rates of iRPL.

The association of APOH and NCF1 polymorphisms on susceptibility to recurrent pregnancy loss in women with antiphospholipid syndrome

BACKGROUND

Recurrent pregnancy loss (RPL) is the main manifestation of pathological pregnancy in antiphospholipid syndrome (APS) women. The immune state plays a significant role in the occurrence/development of APS and RPL susceptibility, but there is little research on genetic factors.

METHOD

Previous studies have described the important role of APOH and NCF1 in APS and pregnancy. To explore the association of APOH and NCF1 gene variants with RPL susceptibility in APS patients, we collected and analyzed 871 controls, 182 APS and RPL, and 231 RPL patients. Four single nucleotide polymorphisms (SNPs) (rs1801690, rs52797880, and rs8178847 of APOH and rs201802880 of NCF1) were selected and genotyped.

RESULTS

We found rs1801690 (p = 0.001, p = 0.003), rs52797880 (p = 8.73e-04, p = 0.001), and rs8178847 (p = 0.001, p = 0.001) of APOH and rs201802880 (p = 3.77e-26, p = 1.31e-26) of NCF1 showed significant differences between APS and RPL patients and controls in allelic and genotype frequencies respectively. Moreover, rs1801690, rs52797880, and rs8178847 showed strong linkage disequilibrium. Especially, our results revealed a complete linkage disequilibrium (D' = 1) between rs52797880 and rs8178847. Furthermore, higher serum TP (total protein) level was described in APOH rs1801690 CG/GG (p = 0.007), rs52797880 AG/GG (p = 0.033), and rs8178847 CT/TT (p = 0.033), while the higher frequency of positive serum ACA-IgM was found in NCF1 rs201802880 GA (p = 0.017) in APS and RPL patients.

CONCLUSION

Rs1801690, rs52797880, and rs8178847 of APOH and rs201802880 of NCF1 were associated with RPL susceptibility in APS patients.

miR-526b-5p/c-Myc/Foxp1 participates in recurrent spontaneous abortion by regulating the proliferation, migration, and invasion of trophoblasts

PURPOSE

As a member of the C19MC family, miR-526b-5p is mainly expressed in the placental tissue and is a well-known tumor suppressor microRNA. However, its effect on the function of trophoblasts and its role in the development of recurrent spontaneous abortion (RSA) remains unclear.

METHODS

Transcriptome sequencing, quantitative real-time polymerase chain reaction (RT-qPCR), Western blot, 5-ethynyl-2'-deoxyuridine (Edu) proliferation analysis, cell counting kit-8 (CCK8) assay, Transwell assays, and wound healing were used to detect the proliferation, migration, and invasion capacity of trophoblasts. Target genes of miR-526b-5p were obtained by the dual luciferase reporter system. The promoter-reporter system and ChIP-qPCR were used to prove that c-Myc positively regulated the expression of Foxp1 RESULTS: The miR-526b-5p levels were significantly higher in patients with RSA than in controls. High expression of miR-526b-5p inhibited the proliferation, migration, and invasion of trophoblast cell line. By contrast, low expression of miR-526b-5p promoted the proliferation and migration of trophoblast cell line. Target genes of miR-526b-5p were c-Myc and Foxp1. c-Myc positively regulated the expression of Foxp1 by binding to the Foxp1 promoter location -146/-135. Finally, miR-526b-5p impeded the proliferation, migration, and invasion of trophoblasts by negatively regulating c-Myc by rescue experiments.

CONCLUSION

Thus, miR-526b-5p affected the proliferation, migration, and invasion of trophoblasts by targeting c-Myc and Foxp1. Low expression of c-Myc further deactivated the positive transcriptional regulation of c-Myc on Foxp1, which may be the mechanism of RSA. This study provides potential therapeutic targets and clues for the diagnosis and treatment of RSA.