Recurrent miscarriage: current concepts in diagnosis and treatment

Untargeted metabolomics analysis reveals the metabolic disturbances and exacerbation of oxidative stress in recurrent spontaneous abortion

BACKGROUND

Recurrent spontaneous abortion (RSA) is characterized by the occurrence of two or more consecutive spontaneous abortions, with a rising prevalence among pregnant women and significant implications for their physical and mental well-being. The multifaceted etiology of RSA has posed challenges in unraveling the molecular mechanisms underlying that underlie its pathogenesis. Oxidative stress and immune response have been identified as pivotal factors in the development of its condition.

METHODS

Eleven serum samples from healthy pregnant women and 17 from RSA were subjected to liquid chromatography/mass spectrometry (LC-MS) analysis. Multivariate statistical analysis was employed to excavate system-level characterization of the serum metabolome. The measurement of seven oxidative stress products, namely superoxide dismutase (SOD), catalase (CAT), malonaldehyde (MDA), glutathione (GPx), glutathione peroxidase (GSH), oxidized glutathione (GSSG), heme oxygenase (HO-1), was carried out using ELISA.

RESULTS

Through the monitoring of metabolic and lipid alternations during RSA events, we have identified 816 biomarkers that were implicated in various metabolic pathways, including glutathione metabolism, phosphonate and phosphinate metabolism, nucleotide metabolism, sphingolipid metabolism, lysine degradation and purine metabolism, etc. These pathways have been found to be closely associated with the progression of the disease. Our finding indicated that the levels of MDA and HO-1 were elevated in the RSA group compared to the control group, whereas SOD, CAT and GPx exhibited a contrary pattern. However, no slight difference was observed in GSH and GSSG levels between the RSA group and the control group.

CONCLUSION

The manifestation of RSA elicited discernible temporal alternations in the serum metabolome and biochemical markers linked to the metabolic pathways of oxidative stress and immune response. Our investigation furnished a more comprehensive analytical framework encompassing metabolites and enzymes associated with oxidative stress. This inquiry furnished a more nuanced comprehension of the pathogenesis of RSA and established the ground work for prognostication and prophylaxis.

The impact of early pregnancy metabolic disorders on pregnancy outcome and the specific mechanism

Miscarriage is the most common complication of pregnancy. The most common causes of early miscarriage are chromosomal abnormalities of the embryo, maternal endocrine abnormalities, organ malformations, and abnormal immune factors. Late miscarriages are mostly caused by factors such as cervical insufficiency. However, the causes of 50% of miscarriages remain unknown. Recently, increasing attention has been given to the role of metabolic abnormalities in miscarriage. In this review, we mainly discuss the roles of four major metabolic pathways (glucose, lipid, and amino acid metabolism, and oxidation‒reduction balance) in miscarriage and the metabolism-related genes that lead to metabolic disorders in miscarriage. Depending on aetiology, the current treatments for miscarriage include hormonal and immunological drugs, as well as surgery, while there are few therapies for metabolism. Therefore, we also summarize the drugs for metabolism-related targets. The study of altered metabolism underlying miscarriage not only helps us to understand the mechanisms involved in miscarriage but also provides an important basis for clinical research on new therapies.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/050, May 2022)

Purpose The aim of this guideline is to standardize the diagnosis and therapy of recurrent miscarriage (RM) using evidence from the recent literature. This is done by using consistent definitions, objective evaluations and standardized treatment protocols.

Methods When this guideline was compiled, special consideration was given to previous recommendations in prior versions of this guideline and the recommendations of the European Society of Human Reproduction and Embryology, the Royal College of Obstetricians and Gynecologists, the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine, and a detailed individual search of the literature about the different topics was carried out.

Recommendations Recommendations about the diagnostic and therapeutic procedures offered to couples with RM were developed based on the international literature. Special attention was paid to known risk factors such as chromosomal, anatomical, endocrinological, physiological coagulation, psychological, infectious and immune disorders. Recommendations were also developed for those cases where investigations are unable to find any abnormality (idiopathic RM).

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

BACKGROUND

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

OBJECTIVES

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

DESIGN

A retrospective hospital record-based descriptive study.

SETTING

A tertiary care center in Turkey.

PATIENTS AND METHODS

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

MAIN OUTCOME MEASURES

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

CONCLUSIONS

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

LIMITATIONS

Single-center study and retrospective.

CONFLICT OF INTEREST

None.

Blood serum lipid profiling may improve the management of recurrent miscarriage: a combination of machine learning of mid-infrared spectra and biochemical assays

The present article is focused on developing and validating an efficient, credible, minimally invasive technique based on spectral signatures of blood samples of women with recurrent miscarriage vs. those of healthy individuals who were followed in the Department of Obstetrics and Gynecology for 2 years. For this purpose, blood samples from a total of 120 participants, including healthy women (n=60) and women with diagnosed recurrent miscarriage (n=60), were obtained. The lipid profile (high-density lipoprotein, low-density lipoprotein, triglyceride, and total cholesterol levels) and lipid peroxidation (malondialdehyde and glutathione levels) were evaluated with a Beckman Coulter analyzer system for chemical analysis. Biomolecular structure and composition were determined using an attenuated total reflectance sampling methodology with Fourier transform infrared spectroscopy alongside machine learning technology to advance toward clinical translation. Here, we developed and validated instrumentation for the analysis of recurrent miscarriage patient serum that was able to differentiate recurrent miscarriage and control patients with an accuracy of 100% using a Fourier transform infrared region corresponding to lipids. We found that predictors of lipid profile abnormalities in maternal serum could significantly improve this patient pathway. The study also presents preliminary results from the first prospective clinical validation study of its kind.

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.

Molecular and Physiological Aspects of SARS-CoV-2 Infection in Women and Pregnancy

Whilst scientific knowledge about SARS-CoV-2 and COVID-19 is rapidly increasing, much of the effects on pregnant women is still unknown. To accommodate pregnancy, the human endometrium must undergo a physiological transformation called decidualization. These changes encompass the remodeling of endometrial immune cells leading to immunotolerance of the semi-allogenic conceptus as well as defense against pathogens. The angiotensin converting enzyme 2 (ACE2) plays an important regulatory role in the renin-angiotensin-system (RAS) and has been shown to be protective against comorbidities known to worsen COVID-19 outcomes. Furthermore, ACE2 is also crucial for decidualization and thus for early gestation. An astounding gender difference has been found in COVID-19 with male patients presenting with more severe cases and higher mortality rates. This could be attributed to differences in sex chromosomes, hormone levels and behavior patterns. Despite profound changes in the female body during pregnancy, expectant mothers do not face worse outcomes compared with non-pregnant women. Whereas mother-to-child transmission through respiratory droplets during labor or in the postnatal period is known, another question of in utero transmission remains unanswered. Evidence of placental SARS-CoV-2 infection and expression of viral entry receptors at the maternal-fetal interface suggests the possibility of in utero transmission. SARS-CoV-2 can cause further harm through placental damage, maternal systemic inflammation, and hindered access to health care during the pandemic. More research on the effects of COVID-19 during early pregnancy as well as vaccination and treatment options for gravid patients is urgently needed.

Epigenetic changes occur in placentas of spontaneous and recurrent miscarriages

BACKGROUND

In contrast to genetic abnormalities which are well known to be responsible for around 50 % of human miscarriages, there is very few data about epigenetic alterations in spontaneous and recurrent miscarriages (SM, RM). The aim of this study was to analyze the histone modification marks H3K9ac and H3K4me3 in SM and RM.

METHODS

The abundance of histone modifications H3K4me3/H3K9ac was analyzed by western blot in frozen abortion material of SM and RM compared to a control group of legal pregnancy terminations. Further, to characterize placental tissue cells expressing H3K4me3/H3K9ac immunohistochemistry (IHC) and immunofluorescence was performed in 20 SM, 19 RM and 26 controls.

RESULTS

The western blot data showed a tendency to an overall reduction of H3K4me3/H3K9ac, in the placental tissue of particularly SM. Further we differentiated between syncytiotrophoblast, cytotrophoblast and decidual cells and found a significant decrease of H3K4me3 in SM in cytotrophoblast cells and syncytial stroma. In RM H3K4me3 was downregulated exclusively in the syncytiotrophoblast. H3K9ac was reduced in SM and RM in all evaluated compartments, except from the syncytiotrophoblast.

CONCLUSION

Our study showed an overall reduced histone modification of H3K4me3 and H3K9ac in the placental tissue of SM. Concerning RM, particularly the reduction of H3K9ac was detected in the placental tissue, indicating that RM group has distinct profile in epigenetic regulation. Whether these histone modifications are part of a possible pathophysiologic cascade during SM and RM or are merely indicating a defective placentation, cannot be concluded from this study.

Significantly Low Levels of IgG Antibodies Against Oncogenic Merkel Cell Polyomavirus in Sera From Females Affected by Spontaneous Abortion

Merkel cell polyomavirus (MCPyV) is a small DNA tumor virus ubiquitous in humans. MCPyV establishes a clinically asymptomatic lifelong infection in healthy immunocompetent individuals. Viral infections are considered to be risk factors for spontaneous abortion (SA), which is the most common adverse complication of pregnancy. The role of MCPyV in SA remains undetermined. Herein, the impact of MCPyV infection in females affected by SA was investigated. Specifically, an indirect enzyme-linked immunosorbent assay (ELISA) method with two linear synthetic peptides/mimotopes mimicking MCPyV antigens was used to investigate immunoglobulin G (IgG) antibodies against MCPyV in sera from 94 females affected by SA [mean ± standard deviation (SD) age 35 ± (6) years] and from 96 healthy females undergoing voluntary pregnancy interruption [VI, mean (±SD) age 32 ± (7) years]. MCPyV seroprevalence and serological profiles were analyzed. The overall prevalence of serum IgG antibodies against MCPyV was 35.1% (33/94) and 37.5% (36/96) in SA and VI females, respectively (p > 0.05). Notably, serological profile analyses indicated lower optical densities (ODs) in females with SA compared to those undergoing VI (p < 0.05), thus indicating a reduced IgG antibody response in SA females. Circulating IgGs were identified in sera from SA and VI females. Our immunological findings indicate that a relatively reduced fraction of pregnant females carry serum anti-MCPyV IgG antibodies, while SA females presented a more pronounced decrease in IgG antibody response to MCPyV. Although yet to be determined, this immunological decrease might prompt an increase in MCPyV multiplication events in females experiencing abortive events. The role of MCPyV in SA, if present, remains to be determined.

Autoantibodies in association with subchorionic haematoma in early pregnancy

OBJECTIVE

To explore the possible aetiology of subchorionic haematoma (SCH), especially its association with autoantibodies.

MATERIAL AND METHODS

Early pregnant women who were detected SCH through ultrasonography were identified as the study group and those without SCH at comparable ages who visited the clinic at the same period of time were compared as the control group. Indexes of laboratory immune tests were compared between the two groups, as well as their pregnancy outcomes.

RESULTS

A total of 97 SCH patients and 130 control cases were recruited in this study. A higher proportion of women was detected autoantibodies in the SCH group compared with control group (45.36% vs 21.54%, p = .000). Positive rates of ANA (24.74% vs 10.77%, p = .005) and laboratory antiphospholipid antibodies (ACL, anti-β2 GP1 or LA) (25.77% vs 11.54%, p = .005) showed significant differences between the two groups. The incidence of vaginal bleeding was significantly higher in the SCH group (43.30% vs 20.00%, p = .000). While the miscarriage rates were not significantly different (17.53% vs 15.38%, p = .666). And there were no significant differences in terms of preterm delivery rate, caesarean section rate, birth weight and pregnancy complications. Most SCHs (96.25%) were absorbed before 20th gestational week. In the SCH group, the average birth weight was significantly lower in women with autoantibodies. Clinical features and other pregnancy outcomes showed no significant differences between SCH patients with and without autoantibodies.

CONCLUSIONS

The occurrence of SCH may be associated with autoantibodies. The pregnancy outcomes were comparable between women with and without SCH.KEY MESSAGESSubchorionic haematoma (SCH) is increasingly commonly observed in early pregnancy period, but the aetiology is uncertain and the clinical significance of SCH is controversial.The occurrence of SCH may be associated with autoantibodies.The pregnancy outcomes were not significantly different between women with and without SCH.

Screening of Candidate Pathogenic Genes for Spontaneous Abortion using Whole Exome Sequencing

BACKGROUND

Spontaneous abortion is a common disease in obstetrics and reproduction.

OBJECTIVE

This study aimed to screen candidate pathogenic genes for spontaneous abortion using whole-exome sequencing.

METHODS

Genomic DNA was extracted from abortion tissues of spontaneous abortion patients and sequenced using the Illumina HiSeq2500 high-throughput sequencing platform. Whole exome sequencing was performed to select harmful mutations, including SNP and insertion and deletion sites, associated with spontaneous abortion. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses and gene fusion analyses were performed. MUC3A and PDE4DIP were two novel mutation genes that were screened and verified by PCR in abortion tissues of patients.

RESULTS

A total of 83,633 SNPs and 13,635 Indel mutations were detected, of which 29172 SNPs and 3093 Indels were screened as harmful mutations. The 7 GO-BP, 4 GO-CC, 9 GO-MF progress, and 3 KEGG pathways were enriched in GO and KEGG pathway analyses. A total of 746 gene fusion mutations were obtained, involving 492 genes. MUC3A and PDE4DIP were used for PCR verification because of their high number of mutation sites in all samples.

CONCLUSION

There are extensive SNPs and Indel mutations in the genome of spontaneous abortion tissues, and the effect of these gene mutations on spontaneous abortion needs further experimental verification.

Effects of aspirin, vitamin D3, and progesterone on pregnancy outcomes in an autoimmune recurrent spontaneous abortion model

High proportions of placental lymphocytes expressing DX5+/CD25+/FOXP3+/CD45+/CD4+ are beneficial to maintain immune tolerance and improve pregnancy outcomes. This study aimed to compare and evaluate the therapeutic effects of aspirin, vitamin D3 (VitD3), and progesterone on the autoimmune recurrent spontaneous abortion (RSA) model. The autoimmune RSA mouse model was constructed, and the embryo loss rate was calculated for each group. Then, primary mouse placental lymphocytes were isolated, and the expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ was detected through flow cytometry. The serum levels of anti-cardiolipin antibody (ACA), β2-GP1, CXCL6, IFN-γ, and IL-6 were measured by ELISA to evaluate the proportion of Th1 and Th2 cells. Autoimmune RSA significantly increased the embryo loss rate, which was improved by aspirin, VitD3, and progesterone treatment, and progesterone treatment had the best effect among the three treatments. The positive expression of DX5+/CD25+/FOXP3+/CD45+/CD4+ in the VitD3 and progesterone groups was significantly higher than that in the autoimmune RSA group, and the expression was highest in the progesterone treatment group. In the plasma of autoimmune RSA mice, the ACA, β2-GP1, CXCL6, and IFN-γ levels were significantly higher and the IL-6 level was lower than the levels in control mice. All these changes could be reversed by aspirin and progesterone treatment. In conclusion, aspirin, VitD3 and progesterone treatment improved pregnancy outcomes in autoimmune RSA mice by regulating the Th1/Th2 balance and cytokines, and progesterone had the best effect of the three treatments.

NKG2D Natural Killer Cell Receptor-A Short Description and Potential Clinical Applications

Natural Killer (NK) cells are natural cytotoxic, effector cells of the innate immune system. They can recognize transformed or infected cells. NK cells are armed with a set of activating and inhibitory receptors which are able to bind to their ligands on target cells. The right balance between expression and activation of those receptors is fundamental for the proper functionality of NK cells. One of the best known activating receptors is NKG2D, a member of the CD94/NKG2 family. Due to a specific NKG2D binding with its eight different ligands, which are overexpressed in transformed, infected and stressed cells, NK cells are able to recognize and attack their targets. The NKG2D receptor has an enormous significance in various, autoimmune diseases, viral and bacterial infections as well as for transplantation outcomes and complications. This review focuses on the NKG2D receptor, the mechanism of its action, clinical relevance of its gene polymorphisms and a potential application in various clinical settings.

The decidual expression of Interleukin-7 is upregulated in early pregnancy loss

BACKGROUND

Maternal immunological rejection of the semi-allogenic fetus is discussed as one of the significant factors involved in early pregnancy loss. An array of cytokines secreted by both maternal and fetal cells is involved in generating a delicate maternal immune tolerance. Interleukin-7 (IL-7) is discussed to play a key role in pro-inflammatory processes, but there is still limited insight into the pathophysiological input on placentation and embryonic development in early pregnancy loss.

PATIENTS AND METHODS

Cytokine level differences were identified with quantitative real-time PCR in placental tissue from spontaneous abortions (SA) (n = 18), recurrent spontaneous abortions (RSA) (n = 15), and healthy pregnancies (n = 15) at gestational weeks 7 to 14. Protein expression of IL-7 in the decidua was investigated by immunohistochemistry. IL-7-expressing cells were identified with double-immunofluorescence.

RESULTS

Decidua of women with RSA expressed almost 51-times higher values of IL-7 in gene expression analysis. Immunohistochemistry identified a significant upregulation of IL-7 in the decidua of RSA specimens (p = .013) and in the decidua of women with SA (p = .004). Double-immunofluorescence confirmed decidual stroma cells as IL-7-expressing cells.

CONCLUSION

Significantly elevated IL-7 values in the decidua of spontaneous and recurrent miscarriages imply a crucial role of the cytokine in the signaling at the feto-maternal interface of the placenta. An overexpression of IL-7 could result in early pregnancy loss by inducing a pro-inflammatory environment. Proven to be valuable in other autoimmune diseases, targeting IL-7 signaling therapeutically may prove to be a very beneficial treatment option for RSA patients.

Association of Tumor Necrosis Factor-α -308G>A, -238G>A and -376G>A polymorphisms with recurrent pregnancy loss risk in the Greek population

Background

Promoter region SNPs in TNF-α have been studied in association with Recurrent Pregnancy Loss (RPL) occurrence in various populations. Among them, −238G > A, −308G > A and − 376G > A have been frequently investigated for their potential role in recurrent abortions. The aim of the present study is to evaluate the correlation among TNF-α 238, TNF-α 308 and TNF-α 376 polymorphisms and recurrent pregnancy loss risk in Greek women.

Methods

This study included 94 Caucasian women with at least two miscarriages of unexplained aetiology, before the 20th week of gestation. The control group consisted of 89 Caucasian women of proven fertility, with no history of pregnancy loss. DNA samples were subjected to PCR amplification using specific primers. Sanger sequencing was applied to investigate the presence of TNF-α 238, TNF-α 308, TNF-α 376 polymorphisms in all samples.

Results

The TNF-α 238 and TNF-α 308 variants were both detected in RPL and control groups (7.45% vs 4.49 and 45.16% vs 36.73%, respectively), but with no statistically significant association (p-value 0.396 and 0.374, respectively). The TNF-α 376 variant was not detected at all in both control and RPL groups. When TNF-α 238 and TNF-α 308 genotypes were combined no association with RPL was detected (p-value = 0.694). In subgroup analysis by parity, RPL patients carrying the A allele reported less previous births.

Conclusions

This is the first study demonstrating TNF-α 238 and TNF-α 308 gene expression and the absence of TNF-α 376 variant in Greek women with RPL. However, no association emerged between each polymorphism studied and the occurrence of recurrent pregnancy loss. Accordingly, TNF-α -308G > A, −238G > A and -376G > A variants are not considered genetic markers for identifying women at increased risk of recurrent pregnancy loss in the Greek population.

Evaluation of Apoptosis, Proliferation, and Adhesion Molecule Expression in Trophoblastic Tissue of Women With Recurrent Spontaneous Abortion and Infected With Toxoplasma gondii

Recurrent spontaneous abortion is an obstetric complication with undefined causes. Apoptosis, proliferation, and adhesion are considered important factors in the pathogenesis of abortion. This work aimed to determine Bax and Bcl-2 as a proapoptotic and antiapoptotic protein, Ki67 and P27kip as proliferative and antiproliferative proteins, and E-cadherin and CD44 as adhesion molecules in the trophoblastic tissues in cases with recurrent miscarriage. Immunohistochemistry and quantitative polymerase chain reaction analysis of Bax, Bcl-2, Ki67, P27kip, E-cadherin, and CD44 in paraffin-embedded sections of placental tissues obtained from 108 women were divided into 3 categories: 66 Toxoplasma gondii-positive women with recurrent abortion, 22 T. gondii-negative women with recurrent abortion, and 20 women with no history of abortion as a control group. The mean ratio of the expression of Bax and P27kip proteins was 35.3% and 36.1%, which is significantly higher than that of the second group (19.88 and 20.02%), and the third group (12.3% and 10.98%), while the mean ratio of the expression of Bcl-2, Ki67, E-cadherin, and CD44 proteins was 12.35%, 11.23%, 10.32%, and 9.97%, which is significantly lower than that of the second group (33.75%, 13.18%, 21.88%, and 23.29%) and that of the third group (38.58%, 39.27%, 37.98%, and 35.79%). The presence of proapoptotic protein (Bax) and antiproliferative protein (P27kip) at high levels and the presence of antiapoptotic protein (Bcl-2), proliferative protein (Ki67), and adhesion molecules (E-cadherin and CD44) in lower levels in the T. gondii-positive group clarify the mechanism involved in the induction of abortion and loss of pregnancy.

Clinical practice guidelines for recurrent miscarriage in high-income countries: a systematic review

Recurrent miscarriage affects 1-2% of women of reproductive age, depending on the definition used. A systematic review was conducted to identify, appraise and describe clinical practice guidelines (CPG) published since 2000 for the investigation, management, and/or follow-up of recurrent miscarriage within high-income countries. Six major databases, eight guideline repositories and the websites of 11 professional organizations were searched to identify potentially eligible studies. The quality of eligible CPG was assessed using the Appraisal of Guidelines for Research and Evaluation (AGREE II) Tool. A narrative synthesis was conducted to describe, compare and contrast the CPG and recommendations therein. Thirty-two CPG were included, from which 373 recommendations concerning first-trimester recurrent miscarriage were identified across four sub-categories: structure of care (42 recommendations, nine CPG), investigations (134 recommendations, 23 CPG), treatment (153 recommendations, 24 CPG), and counselling and supportive care (46 recommendations, nine CPG). Most CPG scored 'poor' on applicability (84%) and editorial independence (69%); and to a lesser extent stakeholder involvement (38%) and rigour of development (31%). Varying levels of consensus were found across CPG, with some conflicting recommendations. Greater efforts are required to improve the quality of evidence underpinning CPG, the rigour of their development and the inclusion of multi-disciplinary perspectives, including those with lived experience of recurrent miscarriage.

The Variations of Metabolic Detoxification Enzymes Lead to Recurrent Miscarriage and Their Diagnosis Strategy

Spontaneous abortion has been a common obstetrical and gynecological disease, which occurs in 10-15% of all pregnancies. Recurrent miscarriage (RM) refers to the occurrence of three or more times abortions with the same partner. It is generally believed that environmental pollution associated with economic development may cause infertility and RM. When xenobiotics from the environment enter the body, they must be cleared from the body by various metabolic enzymes in the body. The absence or variation of these enzymes may be the genetic basis of RM caused by environmental pollution. The variation of metabolic detoxification enzyme can directly affect the removal of harmful substances from internal and external sources. Therefore, the determination of metabolic enzyme activity may become an important factor in the diagnosis of RM etiology and seeking methods to improve the detoxification ability has a great significance for the treatment of RM.

Interleukin-1 beta is significantly upregulated in the decidua of spontaneous and recurrent miscarriage placentas

BACKGROUND

Pregnancy is an extraordinarily complex immunological process. For successful pregnancy maintenance the maternal immune system must adapt to and tolerate the semi-allogenic fetus at the fetomaternal interface of the placenta. This balance is regulated by cytokines with a predominant T helper 2 (Th-2) system and a suppressed inflammatory T helper 1 (Th-1) response. This study investigates the role of the Th-1 pro-inflammatory cytokine Interleukin-1 beta (IL-1β) and its role in early pregnancy loss.

PATIENTS AND METHODS

In order to identify differences in IL- β levels a TaqMan® Human Cytokine Network Array, with placental tissue obtained from patients with healthy pregnancies (n = 15) and recurrent miscarriage (n = 15), was carried out. Protein expression of IL-1β in the decidua of healthy pregnancies (n = 15), spontaneous (n = 18) and recurrent miscarriages (n = 15), was investigated by immunohistochemistry. The identification of IL-1β expressing cells in the decidua was done with double-immunofluorescence.

RESULTS

Gene expression analysis identified a nearly 54-times higher expression of IL-1β in placental tissue of patients suffering from recurrent abortion. Immunohistochemistry confirmed a significant upregulation of IL-1β in the decidua of recurrent miscarriage specimens (p = 0.01) as well as in the decidua of women with spontaneous abortion (p = 0.001). Double-immunofluorescence identified decidual stoma cells as IL-1β expressing cells.

CONCLUSION

Significant upregulation of IL-1β may be associated with an imbalanced immune system and a procoagulant state that could be responsible for early pregnancy loss. These results provide new evidence of the complex interplay of IL-1β at the fetomaternal interface and its crucial role in miscarriage processes.

The SERPINA4 rs2070777 AA Genotype is Associated with an Increased Risk of Recurrent Miscarriage in a Southern Chinese Population

Background

Many inflammation-related gene polymorphisms are associated with susceptibility to recurrent miscarriage. SERPINA4 is involved in inflammation and is associated with susceptibility to a variety of diseases, but its relevance in recurrent miscarriage is unclear. Therefore, this study aimed to investigate the relationship between SERPINA4 gene polymorphisms and susceptibility to recurrent spontaneous abortion.

Methods

Two SERPINA4 polymorphisms were genotyped in 631 patients with recurrent miscarriage and 771 controls by TaqMan real-time polymerase chain reaction, and the strength of each association was evaluated through 95% confidence intervals (CIs) and odds ratios (ORs).

Results

The results showed that SERPINA4 rs2070777 AA genotypes were associated with an increased risk of recurrent miscarriage (AA vs AT/TT adjusted OR=1.409, 95% CI=1.032–1.924, P=0.0309), and we also found a significant association between the rs910352 T allele in the SERPINA4 gene and susceptibility to recurrent miscarriage (CT vs CC adjusted OR=1.579, 95% CI=1.252–1.992, P=0.0001; TT vs CC adjusted OR=1.524, 95% CI=1.134–2.049, P=0.0052). The combined analysis of two SNPs of the SERPINA4 gene revealed that carriers with one to two unfavorable genotypes were associated with a higher risk for recurrent miscarriage compared with individuals with no unfavorable genotypes (adjusted OR=1.257, 95% CI=1.019-1.550). Moreover, our study indicates that having one to two unfavorable genotypes is associated with an increased risk of recurrent miscarriage in women 35–40 years of age.

Conclusion

Our study suggests that SERPINA4 rs2070777AA genotypes might contribute to an increased risk of recurrent miscarriage in a southern Chinese population.

Sinomenine Improves Embryo Survival by Regulating Th1/Th2 Balance in a Mouse Model of Recurrent Spontaneous Abortion

Background

This study aims to explore the effect of Sinomenine (SIN) on pregnancy outcomes of recurrent spontaneous abortion (RSA) in a mouse model.

Material/Methods

Thirty female CBA/J mice were allocated into 3 groups randomly, then mated with BALB/c mice (CBA/J×BALB/c) as normal-pregnancy group (n=10), or mated with DBA/2 mice (CBA/J×DBA/2) as RSA model (n=10), or CBA/J×DBA/2 mice treated with SIN as RSA+SIN group (n=10). The number of surviving and reabsorbed embryos in each group were counted on day 13.5 of gestation. The mouse serum was collected to determine the levels of interferon-γ (IFN)-γ and IL-4 by ELISA. Immunohistochemistry, qRT-PCR and immunoblotting were used to determine the location, mRNA and protein expressions of IFN-γ, IL-4, T-bet and GATA3 in the decidual and placental tissue.

Results

In the RSA group, the amount of reabsorbed embryo was significantly higher than that in the normal-pregnancy group. However, SIN treatment showed a rescue effect on spontaneous abortion in RSA mice. IFN-γ, IL-4, T-bet, and GATA3 were all expressed in placental tissues and mainly located in the cytoplasm. The RSA group demonstrated higher expression levels of IFN-γ and T-bet than in the RSA+SIN and normal-pregnancy groups. Although RSA and RSA+SIN groups showed lower expression levels of IL-4 and GATA3 than in the normal-pregnancy group, there was no significant difference between RSA and RSA+SIN groups regarding IL-4 and GATA expression levels.

Conclusions

SIN treatment demonstrates a therapeutic effect on spontaneous abortion in RSA mice, possibly through regulating the balance of Th1/Th2 in maternal circulation and decidual tissues.

Pregnancy Zone Protein (PZP) is significantly upregulated in the decidua of recurrent and spontaneous miscarriage and negatively correlated to Glycodelin A (GdA)

BACKGROUND

Pregnancy Zone Protein (PZP) is an immunosuppressive protein that is expressed by the placenta and has also been identified in immune cells. When PZP and Glycodelin A (GdA) are combined, they act synergistically to inhibit Th-1 immune response. Little is known about its combined expression and role in normal and disturbed first trimester pregnancy.

PATIENTS AND METHODS

We investigated the expression of PZP and GdA in placental tissue obtained from spontaneous miscarriage (SM) (n = 19) and recurrent miscarriage (RM) (n = 17) at gestational weeks 6-13 by immunohistochemistry and on mRNA-level by either TaqMan PCR or in situ hybridization. Placental tissue from legal terminations of healthy pregnancies (n = 15) served as control group. Immunofluorescence double staining was used to analyse the combined expression of PZP and GdA in decidual tissue.

RESULTS

The protein level of PZP was significantly increased in decidual stroma of SM samples compared to the decidua of control specimens and also significantly upregulated in the decidual stroma cells in the RM group. Concerning GdA, the decidual stroma revealed a significantly decreased protein level in the group with spontaneous abortions than in the group with healthy pregnancies. There was also a significant downregulation of GdA in the decidual stroma of RM samples compared to the control group. We observed a significant negative correlation of PZP and GdA in decidual stromal tissue of recurrent abortion. We could confirm the staining results for PZP as well as for GdA on mRNA level. Both proteins are co-localized in decidual stroma as analysed by immunofluorescence double staining.

CONCLUSION

A balanced expression of GdA and its carrier protein PZP in the decidua seems crucial for a successful ongoing pregnancy. According to our data, these immunosuppressive proteins are co-localized in the decidual tissue and show a negative correlation only in patients suffering from recurrent abortion.

Inhibition of microRNA-149 protects against recurrent miscarriage through upregulating RUNX2 and activation of the PTEN/Akt signaling pathway

AIM

Recently, microRNA-149 (miR-149) has been indicated to act as an oncogene or a tumor suppressor in various malignant tumors, while its inner mechanisms in recurrent miscarriage (RM) are still in infancy. Therein, this study intends to decode the mechanism of miR-149 in RM.

METHODS

miR-149 and RUNX2 expression in the chorionic tissues of normal pregnant women and RM patients were first examined, and the correlation between miR-149 and RUNX2 was analyzed. Subsequently, miR-149 was upregulated in HTR-8 cells or downregulated in BEWO cells, and then the changes in biological functions of trophoblasts in RM were detected. Furthermore, the expression of PTEN/Akt signaling pathway-related factors in trophoblasts was detected by western blot analysis.

RESULTS

miR-149 expression was increased while RUNX2 expression was suppressed in RM patients, and miR-149 was negatively correlated with RUNX2. Overexpressed miR-149 induced cell apoptosis and inhibited cell activity, while reduced miR-149 in trophoblasts contributed to opposite experimental results. Moreover, miR-149 promoted the expression of PTEN and inhibited Akt phosphorylation by targeting RUNX2, thereby inhibiting trophoblast activity and promoting their apoptosis.

CONCLUSION

Our study demonstrates that miR-149 knockdown halted the RM development through upregulating RUNX2 and activation of the PTEN/Akt signaling pathway.

BuShen HuoXue Decoction Promotes Decidual Stromal Cell Proliferation via the PI3K/AKT Pathway in Unexplained Recurrent Spontaneous Abortion

BuShen HuoXue decoction (BSHXD) has been used to treat patients with unexplained recurrent spontaneous abortion (URSA). However, the chemical compounds and mechanism by which BSHXD exerts its therapeutic and systemic effects to promote the proliferation of decidual stromal cells (DSCs) has not been elucidated. This work sought to elucidate the cellular and molecular mechanism of BSHXD in terms of inflammatory factors IL-17A in DSCs in vitro because of the critical roles of inflammation, apoptosis, and immunity in the development and progression of pregnancy loss. Twelve migratory chemical compounds from BSHXD extract were qualitatively analyzed by high-performance liquid chromatography (HPLC). DSCs were collected from normal early pregnancy (NEP) and URSA to determine whether BSHXD affects IL-17A/IL17RA via the PI3K/AKT pathway. Abnormal apoptosis and activated p-AKT were observed in URSA DSCs. RhIL-17 A, LY294002 (a PI3K pathway inhibitor), and BSHXD were individually or simultaneously administered in NEP DSCs, suggesting that BSHXD restored cell proliferation without excessive stimulation and IL-17A promotes proliferation via the PI3K/AKT pathway. Using the same intervention in URSA DSCs, qRT-PCR measured the upregulated mRNA levels of IL-17 A/IL-17RA, PI3K, AKT, p-AKT, PTEN, Bcl-2, and Bcl-xL and downregulated mRNA levels of BAD and ACT1 after treatment with BSHXD. We demonstrated that BSHXD affected IL-17A/IL-17R via PI3K/AKT pathway to promote the proliferative activity of DSCs in URSA. These results provide a new insight to further clarify the relationship between inflammation and apoptosis and the mechanism of imbalance in the dynamic equilibrium between Th17/Treg immune cells at the maternal-fetal interface.

Investigation on Spontaneous Abortion and Human Papillomavirus Infection

Viral infections are considered to be risk factors for spontaneous abortion (SA). Conflicting results have been reported on the association between Human Papillomavirus (HPV) and SA. HPV DNA was investigated in matched chorionic villi tissues and peripheral blood mononuclear cells (PBMCs) from women who experienced SA (n = 80, cases) and women who underwent a voluntary interruption of pregnancy (VI; n = 80, controls) by qualitative PCR and quantitative droplet digital PCR (ddPCR). Viral genotyping was performed using real-time PCR in HPV-positive samples. Specific IgG antibodies against HPV16 were investigated in sera from SA (n = 80) and VI (n = 80) females using indirect ELISA assays. None of the DNA samples from SA subjects was HPV-positive (0/80), whilst HPV DNA was detected in 2.5% of VI women (p > 0.05), with a mean viral DNA load of 7.12 copy/cell. VI samples (n = 2) were found to be positive for the HPV45 genotype. The ddPCR assay revealed a higher number of HPV-positive samples. HPV DNA was detected in 3.7% and 5% of SA and VI chorionic tissues, respectively, with mean viral DNA loads of 0.13 copy/cell in SA and 1.79 copy/cell in VI (p >0.05) samples. All DNA samples from the PBMCs of SA and VI females tested HPV-negative by both PCR and ddPCR. The overall prevalence of serum anti-HPV16 IgG antibodies was 37.5% in SA and 30% in VI (p > 0.05) women. For the first time, HPV DNA was detected and quantitatively analyzed using ddPCR in chorionic villi tissues and PBMCs from SA and VI women. Circulating IgG antibodies against HPV16 were detected in sera from SA and VI females. Our results suggest that HPV infection in chorionic villi may be a rare event. Accordingly, it is likely that HPV has no significant role in SA.

Weighted gene correlation network analysis reveals novel regulatory modules associated with recurrent early pregnancy loss

At present, the etiology and pathogenesis of recurrent early pregnancy loss (REPL) are not completely clear. Therefore, identifying the underlying diagnostic and prognostic biomarkers of REPL can provide new ideas for the diagnosis and treatment of REPL. The chip data of REPL (GSE63901) were downloaded from the NCBI Gene Expression Omnibus (GEO) database. Weighted Gene Co-Expression Network Analysis (WGCNA) was used to construct a co-expression module for studying the relationship between gene modules and clinical features. In addition, functional analysis of hub genes in modules of interest was performed. A total of 23 co-expression modules were identified, two of which were most significantly associated with three clinical features. The MEbrown module was positively correlated with cyclin E level and the out-of-phase trait while the MEred module was positively correlated with the effect of progesterone. We identified 17 hub genes in the MEred module. The functional enrichment analysis indicated that such hub genes were mainly involved in pathways related to cellular defense response and natural killer (NK) cell-mediated cytotoxicity. In the MEbrown module, we identified 19 hub genes, which were mainly enriched in cell adhesion molecule production, regulation of cellular response to growth factor stimulus, epithelial cell proliferation, and transforming growth factor-β (TGF-β) signaling pathway. In addition, the hub genes were validated by using other datasets and three true hub genes were finally obtained, namely DOCK2 for the MEred module, and TRMT44 and ERVMER34-1 for the MEbrown module. In conclusion, our results screened potential biomarkers that might contribute to the diagnosis and treatment of REPL.

Spliceosome protein EFTUD2 is upregulated in the trophoblast of spontaneous miscarriage and hydatidiform mole

BACKGROUND

Elongation factor Tu GTP binding domain containing 2 (EFTUD2) is an alternative splicing factor that modulates cell differentiation and activation processes. EFTUD2 is known to modulate immune responses and mutation of the EFTUD2-gene lead to fetal malformation. Little is known about its expression and role in normal and disturbed first trimester pregnancy.

PATIENTS AND METHODS

We investigated the expression of EFTUD2 in placental tissue obtained from patients with normal (n = 14), spontaneous miscarriage (n = 15) and molar (n = 14) pregnancy by immunohistochemistry. The expression of EFTUD2 was correlated on the protein level with known immune modulatory proteins like pregnancy zone protein (PZP) and in addition with human chorionic gonadotropin (hCG). Furthermore, we analysed the EFTUD2 and PZP expression in vitro after stimulation of the chorioncarcinoma cell line JEG-3 with hCG.

RESULTS

EFTUD2 is significantly upregulated in the syncytiotrophoblast of spontaneous miscarriage (p = 0.003) and molar pregnancy (p = 0.003) compared to week of gestation-adjusted normal first trimester placentas. PZP is negatively correlated (p = 0.021) to EFTUD2 in the syncytiotrophoblast and is therefore significantly downregulated in miscarriage (p = 0.028) and mole pregnancy (p = 0.006). In addition, hCG is positively correlated to EFTUD2 in mole pregnancy. The addition of hCG to chorioncarcinoma cell lines JEG-3 in vitro stimulated EFTUD2 expression in these cells (p = 0.027).

CONCLUSION

Regulation of alternative splicing seems crucial for a successful ongoing pregnancy. The up-regulated elongation factor EFTUD2 may have a critical role in miscarriage.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Recurrent Pregnancy Loss in Women with Hashimoto's Thyroiditis with Concurrent Non-Endocrine Autoimmune Disorders

Background: An increased rate of recurrent miscarriage has been described in patients with autoimmune thyroid disease. However, there is a lack of studies that assess the rate of recurrent pregnancy loss (RPL) in patients with Hashimoto's thyroiditis (HT) isolated or with concurrent non-endocrine autoimmune disorders (NEAD). The objective of the study was to assess the rate of RPL in patients with HT isolated or accompanied with non-endocrine autoimmune diseases. Methods: This is a retrospective observational cohort study with a systematic review of the NEAD with concurrent HT in an outpatient Endocrinology Unit at a University Hospital. Among the 3480 consecutively examined women with HT, 87 patients met the criteria of RPL and represented the study group. Sixty-five of them had isolated HT and 22 women had HT+NEAD. Results: The rate of RPL in women with HT was 2.1% versus 5.64% observed in women with HT+NEAD (odds ratio = 2.78 [95% confidence interval 1.70-4.57]; p < 0.0001). On subdivision, this difference was still evident in euthyroid patients (p < 0.0001), while it disappeared in hypothyroid women (p = 0.21). The RPL did not correlate with the autoantibody concentrations nor in women with isolated HT nor in those with HT+NEAD. The presence of antiphospholipid syndrome (APS) explained RPL in 3 out of 22 (14%) patients with HT+NEAD, the remaining being related to different autoimmune disorders. Interestingly, even subtracting the patients with APS, RPL was more frequent in patients with poly-autoimmunity than in patients with isolated HT (p = 0.0013). Conclusions: The co-presence of NEAD is correlated with a higher risk of RPL in women with HT. The association with APS may explain only a fraction of RPL rate in patients with poly-autoimmunity.

NK cell subsets in idiopathic recurrent miscarriage and renal transplant patients

The present review article compares NK cell subsets and cytokine patterns determined in the peripheral blood as well as results of functional in-vitro assays using peripheral NK cells of idiopathic recurrent miscarriage (iRM) patients with corresponding results obtained in female healthy controls and female renal transplant recipients with good long-term graft function. Immune mechanisms, inducing transplant rejection in long-term transplant recipients might also be able to induce rejection of semi-allogeneic fetal cells in patients with iRM. Consequently, the immune status of transplant recipients with good stable long-term graft function should be different from the immune status of iRM patients. iRM patients show a strong persistent cytotoxic NK cell response in the periphery. Simultaneously, immunostimulatory Th1 as well as immunosuppressive Th2 type lymphocytes in the blood are strongly activated but plasma levels of immunosuppressive Th2 type cytokines are abnormally low. In-vitro, unstimulated NK cell cultures of iRM patients show a strong spontaneous TGF-ß1 release in the supernatant but lower TGF-ß1 levels after stimulation with tumor cell line K562, suggesting strong consumption of TGF-ß1 by pre-activated NK cells of iRM patients that might contribute to the low systemic Th2 type plasma levels. iRM patients do not show a systemic switch to a Th2 type cytokine pattern and one might hypothesize that low TGF-ß plasma levels indicate low TGF-ß levels in the micromilieu immediately before fetal rejection. Persistent TGF-ß deficiency implies a persistent unfavorable micromilieu for pregnancy resulting in failing tolerance induction due to lack of TGF-ß, a condition that might contribute to iRM.

Associations between tumor necrosis factor-α and interleukin-6 polymorphisms and unexplained recurrent spontaneous abortion risk: A meta-analysis

To evaluate the associations between Tumor necrosis factor-α (TNF-α)(-238G>A) and Interleukin-6 (IL-6)(-174G>C) polymorphism and risk of unexplained recurrent spontaneous abortion (URSA).Correlated case-control studies were collected by computer retrieval. A meta-analysis was conducted by Stata 12.0 software to analysis the strength of association between polymorphism of TNF-α -238G>A and IL-6 -174G>C and URSA.Twenty-one articles with twenty-two studies were included, of which 12 and 10 studies were respectively related to mutation of TNF-α -238G>A, IL-6 -174G>C and URSA. The integrated results showed that the TNF-α-238G>A gene mutation was significantly correlated with the risk of URSA under homozygote model (AA vs GG;OR 1.533,95% CI 1.022-2.301) and recessive model (AA vs GG+AG;OR 1.571,95%CI 1.050-2.350)(P < .05). There was no association between URSA and TNF-α -238G>A under heterozygote model (AG vs GG;OR 0.963,95% CI 0.816-1.137), dominant model (AA+AG vs GG; OR 1.031,95%CI 0.880-1.209) and additive model (A vs G;OR 1.046,95%CI 0.909-1.203)(P > .05). The results of subgroup analysis based on ethnicity showed that -238G>A was significantly correlated with the risk of URSA in Asians under all gene models except for heterozygote model (AG vs GG; OR 1.129,95% CI 0.857-1.487) (P < .05). In Caucasians, it was dominant model (AA+AG vs GG; OR 1.430,95%CI 1.040-1.965) (P < .05) rather than others that showed relationship with URSA. From the integrated results, association was manifested between -174G>C and URSA under all gene models (P < .05) except for recessive model (CC vs GG+CG, OR 1.166, 95%CI 0.938-1.449) (P > .05), which is identical to subgroup analysis based on ethnicity.It is of great guiding significance for screening out and preventing URSA among high-risk women to test on TNF-α -238G>A and IL-6 -174G>C under gene models mentioned above which are highly associated with the risk of URSA, which can act as biological markers for URSA.

Defining the role of FMR1 gene in unexplained recurrent spontaneous abortion

INTRODUCTION

Recurrent spontaneous abortion is a multifactorial disorder and till date, various factors have been attributed in its pathogenesis. Still, approximately 50% of RSA cases remain unexplained. Premutation (PM) expanded allele of fragile-X mental retardation 1 (FMR1) gene is known to contribute to ovarian dysfunction in 20% of the cases. Recently, the link between expanded FMR1 allele and recurrent miscarriages has been reported.

METHOD

In the present prospective case-control study, we have investigated the status of CGG repeat size at 5'UTR of the FMR1 gene in women with unexplained RSA in comparison to age-matched healthy control women (n = 100 each). The genomic DNA from these samples was subjected to molecular analysis for characterization of CGG repeat size and composition at FMR1 gene RESULTS: As compared to the control women, the RSA women cohort had a higher frequency of carriers with alleles in gray zone (GZ) and expanded PM range, i.e., 2% (2/100) versus 5% (5/100), respectively. Also, the RSA cohort had a significantly higher number of normal alleles with ≥ 35 CGG repeats (24 out of 200 alleles) as compared to control cohort (8 out of 200 alleles). The number of larger FMR1 alleles with pure CGG repeat tract was found to be significantly higher (P = 0.0063) in the RSA cohort (15 out of 200 alleles) as compared to that in control cohort (3 out of 200 alleles).

CONCLUSION

Henceforth, the CGG expanded uninterrupted FMR1 allele might be associated with recurrent abortions and may help to explain many of these unexplained cases.

Genetic variation in the maternal vitamin D receptor FokI gene as a risk factor for recurrent pregnancy loss

PURPOSE

Recurrent pregnancy loss (RPL) is a reproductive disorder defined as the loss of two or more pregnancies before 24 weeks of gestation. Despite the fact that several mechanisms have been previously described for the pathogenesis of RPL, the causes of ∼50% of cases remain unknown. However, recent studies indicate association of vitamin D deficiency with adverse pregnancy outcome, including RPL. The vitamin D receptor (VDR) is a crucial mediator of the pleiotropic cellular effects of vitamin D. Its function is influenced by several single nucleotide polymorphisms (SNPs). The main objective of this study is to assess whether maternal VDR SNPs are associated with the risk of RPL in Slovenian and Croatian women.

METHODS

A case-control study including 320 women with RPL and control women is designed to examine the potential association of VDR polymorphisms (FokI rs222857, Cdx2 rs11568820, and Taq1 rs731236) with RPL. Genotyping is performed using polymerase chain reaction and restriction fragment length polymorphism methods.

RESULTS

We find a statistically significant higher frequency of the rs222857 CC genotype (χ² = 6.61, p = .036) and C allele (χ² = 5.93, p = .015) in RPL women compared to controls. Subsequently, the odds for RPL for the rs222857 are increased under the recessive (CCvsCT + TT: OR = 1.78; 95% CI = 1.12-2.82; p = .015) and the codominant (CCvsTT: OR = 2.21; 95% CI = 1.08-4.53; p = .029; CCvsCT: OR = 1.68; 95% CI = 1.04-2.72; p = .036) genetic models. The other two analyzed polymorphisms did not show any statistical significant result.

CONCLUSIONS

Our results suggest that variations in the maternal VDR FokI gene might be associated with RPL in Slovenian and Croatian women.

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.

The role of FAS, FAS-L, BAX, and BCL-2 gene polymorphisms in determining susceptibility to unexplained recurrent pregnancy loss

PURPOSE

Idiopathic recurrent pregnancy loss (RPL) is a multifactorial reproductive disorder where an impaired control of apoptosis is likely involved. Triggering the cell death mechanism occurs in a spatiotemporal manner and is strongly related to a healthy pregnancy. Single nucleotide polymorphisms (SNPs) at the regulatory regions of genes are known to influence the expression patterns of apoptosis-related molecules.

METHODS

A total of 296 unrelated female Brazilian patients were evaluated for clinical-demographic variables and genetic factors: 140 women who had experienced an unexplained RPL (with at least two consecutive abortions) and 156 healthy multiparous women. In all patients, six SNPs were evaluated in genes of apoptosis-related pathways: FAS (rs2234767, rs1800682), FAS-L (rs763110, rs5030772), BAX (rs4645878), and BCL-2 (rs2279115) by PCR followed by a restriction fragment length polymorphism (RFLP)-based analysis.

RESULTS

The BAX-248GA genotype is independently associated with idiopathic RPL [adjusted OR = 0.30, 95% CI 0.13-0.70, P = 0.005] susceptibility. In the same multivariate model, the variables ethnicity, smoking, and alcohol consumption were statistically associated with RPL susceptibility (P < 0.05). No association with RPL susceptibility was reported for the remaining SNPs.

CONCLUSION

Our study is the first to evaluate the role of the main SNPs from both the extrinsic and intrinsic apoptosis pathways in RPL susceptibility. The association of BAX-248G/A with RPL susceptibility suggests that maternal predisposition for RPL has an essential contribution from genes involved in the delicate balance of endometrium cell turnover (cell death/proliferation). Therefore, apoptotic genes may represent promising targets for future studies on healthy pregnancies and the spectrum of pregnancy disorders.

Gene polymorphism associated with endothelial nitric oxide synthase (4VNTR, G894T, C786T) and unexplained recurrent spontaneous abortion risk: A meta-analysis

To evaluate the association between endothelial nitric oxide synthase gene polymorphisms (4VNTR A/B, G894T, C786T) and risk of URSA.Related case-control studies were collected by computers. A meta-analysis was conducted using Stata 12.0 software to assess the strength of association.Altogether 37 articles were examining the relationship between endothelial nitric oxide synthase gene polymorphisms and URSA, among which sixteen (16) studies were related to 4VNTR, twelve (12) to G894T, and nine (9) to C786T, the study suggested that 4VNTR A/B polymorphism was closely connected with URSA risk under all gene models except for recessive model (AA vs. BB + AB). The integrated result which indicated the association between G894T gene mutation and URSA risk had been shown under homozygote (TT vs. GG; OR 1.585, 95%CI 1.175-2.138) and recessive models (TT vs. TG + GG; OR 1.530, 95%CI 1.142-2.052). Considering heterogeneity in the remaining gene models, subgroup analysis was performed on ethnicity, and the results showed that it was the dominant (TT + TG vs. GG; OR 1.585, 95%CI 1.175-2.138) and additive models (T vs. G; OR 1.727, 95%CI 1.372-2.175) of G894T in Asians and the heterozygote model (TG vs. GG; OR 1.015, 95%CI 0.846-1.217) in Caucasians that were associated with URSA (P < .05). Besides C786T gene was significantly connected with URSA under all models except for additive model (T vs. C).It is of great guiding significance for screening out and preventing URSA among high-risk women via testing on 4VNTR A/B, G894T, C786T eNOS under gene models mentioned above which are closely associated with URSA.

Association of Estrogen Receptor 1 Genetic Polymorphisms with Recurrent Spontaneous Abortion Risk

Background:

Estrogen is one of the most important reproductive steroidal hormones and plays a critical role in the maintenance of pregnancy, and its function is mediated by estrogen receptor 1(ESR1). The polymorphisms of ESR1 were involved in recurrent spontaneous abortion (RSA); however, the association between ESR1 polymorphisms and RSA remains controversial. The present meta-analysis was aimed to clarify the association between ESR1 PvuII (-397C/T, rs2234693) and XbaI (-351A/G, rs9340799) polymorphisms and the risk of RSA.

Methods:

All the included articles were retrieved from PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Med Online Database up to January 3, 2018. Data were processed in the Stata 12.0 software. The odds ratios (OR s) and 95% confidence intervals (95% CIs) were calculated using fixed-effects models (FEM)/random-effects models (REM).

Results:

Seven case–control studies with 836 cases and 1164 controls were included in the study. Generally, the ESR1 polymorphisms were not associated with RSA in any of the genetic analysis models. However, it was found that as rs9340799 polymorphism was related to increased risk of RSA in non-Asian group in the homozygous genetic model (OR = 2.40, 95% CI = 1.05–5.50, P = 0.039). Moreover, in Asian group, rs9340799 polymorphism was found to be related to decreased RSA risk in both the heterozygous model (OR = 0.53, 95% CI = 0.33–0.85, P = 0.009) and the dominant genetic model (OR = 0.55, 95% CI = 0.30–0.98, P = 0.042).

Conclusions:

Generally, there was no significant association between the polymorphisms of ESR1 and the risk of RSA. However, subgroup analysis indicated that ESR1 rs9340799 polymorphism was related to increased RSA risk in the non-Asian group while associated with decreased RSA risk in Asian group.

Elevated percentage of CD3+T cells and pregnancy outcome in women with recurrent pregnancy loss

BACKGROUND

Even though the immune factor is not yet established as a cause of recurrent pregnancy loss (RPL), tons of other studies have shown that a significant proportion of immune abnormalities exist in RPL.

METHODS

We conducted a retrospective cohort study with 850 women who were diagnosed with RPL. The percentages of CD3⁺, CD3⁺CD4⁺ and CD3⁺CD8⁺T cells of each participant, detected by flow cytometry, were obtained before pregnancy and at 6 weeks of gestation as part of their routine medical examination.

RESULTS

Peripheral blood CD3⁺ T cells prior to pregnancy (at baseline), increased significantly in women who had a miscarriage compared with the subsequent live birth group. Moreover, the percentage of CD3⁺ and CD3⁺CD4⁺T cells during pregnancy increased significantly as compared with the baseline level. After adjusting for potential confounders, the multiple regression equation showed that the CD3⁺ T cells <67.84% was associated with the risk of miscarriage (OR 1.05, 95% CI, 1.01 to 1.11, p = .04). Additionally, a nonlinear relationship was observed between the percentage of CD3⁺T cells and the risk of miscarriage.

CONCLUSIONS

The risk of miscarriage increased as the percentage of population with CD3+ value below 67.84% has increased, nevertheless, the miscarriage risk did not increase further when the level of CD3⁺T cells was >67.84%.

Dysregulated uterine natural killer cells and vascular remodeling in women with recurrent pregnancy losses

PROBLEM

Angiogenesis and vascular remodeling in secretory endometrium represent one of the crucial steps in pregnancy establishment, for which uterine NK (uNK) cells have an important role. Impairment of these steps may proceed to implantation and instigate initial pathology of recurrent pregnancy losses (RPL). In this study, we aim to investigate vascular development and density of uNK cells in secretory endometrium of women with RPL.

METHODS OF STUDY

Mid-secretory phase endometrial tissues from women with RPL (n = 15) and fertile controls (n = 7) were investigated. CD56⁺ and CD16⁺ uNK cells, CD31⁺ vascular endothelial cells and smooth muscle myosin (SMM)⁺ . Vascular smooth muscle cells (VSMC) expressing SMM were investigated using immunohistochemistry and western blot. High-throughput quantitative real-time polymerase chain reaction (qRT-PCR) was used as well.

RESULTS

CD56⁺ uNK number was significantly higher in women with RPL compared to controls (P < 0.0001). uNK cell density by immunohistochemistry was positively correlated with CD56 mRNA expression by qRT-PCR (r²  = 0.43, P = 0.0137). The number of blood vessels represented by the expression of either CD31 or SMM was higher in women with RPL as compared to controls (P < 0.05 and P < 0.0001, respectively), and correlated with the number of uNK cell (r²  = 0.18, P < 0.04, and r²  = 0.65, P < 0.0001, respectively). The wall thickness of spiral arteries was significantly higher in women with RPL as compared with that of controls (P = 0.0027).

CONCLUSION

Increased uNK cells in mid-secretory endometrium are associated with increased vascularization and defective vascular transformation of spiral arteries in women with RPL.

Advances in Understanding the Immune Imbalance between T-Lymphocyte Subsets and NK Cells in Recurrent Spontaneous Abortion

Recurrent spontaneous abortion is a global problem, and unexplained recurrent abortion triggered by immunological factors is an important focus of current research. Helper T lymphocytes (Th cells) and regulatory T lymphocytes (Treg cells) are central in human immune regulation and play a complex role in pregnancy. Natural killer cells (NK cells) exist in the endometrium and cooperate with T lymphocytes to create immune tolerance at the maternal-fetal interface, which is essential for successful pregnancy. This review has analyzed studies on Th17 cell, Treg cell and NK cell dysfunction and cellular imbalances which may contribute to unexplained recurrent spontaneous abortion to suggest a possible direction for future immunotherapies.

Complement protein and Immunoglobulins Serum levels in Normal Pregnant and Spontaneous Aborted Women

Disorder of maternal immune responses during pregnancy triggers immunological rejection of fetus antigens by maternal immune components, contribute to spontaneous abortion or miscarriage. The study was designed to concentrated on immunoglobulins (IgM, IgG and IgA) and complement elements (C3 and C4)   serum levels changes in normal pregnant and abortion women. Study groups were classified into normal pregnant women (20), spontaneous abortion (30) and non-pregnant women (16) as a control group, attending to Shahid Dr. Khalid Hospital/Department of Gynecology and Obstetrics/Koya city. Serum levels of immunoglobulins (IgG, IgM, and IgA), complement proteins (C3 and C4) were determined and analyzed for normal pregnant, abortion and control groups by using Single Radial Immunodiffusion (SRID) technique. The results demonstrated that concentration of IgG levels in abortion differed significantly in compare to normal pregnancy (p ≤0.05), while there were no significant differences in IgM and IgA serum levels among groups (p >0.05). Also, statistical analysis revealed that serum levels of C3 and C4 significantly decreased in abortion group compared to normal pregnant and non-pregnant groups (p ≤0.05). Concluded that complement proteins (C3 andC4) are a good defense line during normal pregnancy, sometime activation (hyper-consuming) of complement elements may provoke spontaneous abortion, while immunoglobulins are a little role in inducing of miscarriage in pregnant women. 

High Level of APOA1 in Blood and Maternal Fetal Interface Is Associated With Early Miscarriage

Early miscarriage (EM) is one of the most devastating obstetrical complications globally affecting the quality of women's life. In the present study, we aimed to identify proteins that correlate with and could act as biomarkers for EM. We performed 2-dimensional gel electrophoresis in chorionic villi samples followed by mass spectrometry for identification of differential protein expression with EM. Proteomic studies detected a total 124 protein spots, out of which 83 spots were differentially expressed between EM and controls in chorionic villi samples. Matrix assisted laser desorbtion/ionization-time of flight (MALDI-TOF) mass spectrometry analysis revealed Apolipoprotein A1 (APOA1) to be the most upregulated protein in the EM group that was validated by Western blotting and Enzyme-linked immunosorbent assay (ELISA) . We found low but not statistically significant level of APOA1 on 21st day of menstruation in comparison to the 7th day. APOA1 level was observed to be the lowest in the first trimester. Hence, this study suggests that low APOA1 expression is critical in establishing pregnancy and elevated APOA1 expression in chorionic villi correlates with EM. Similar observation in serum samples suggests its potential as a marker for the risk of EM.

PPARγ Expression Is Diminished in Macrophages of Recurrent Miscarriage Placentas

PPARγ belongs to the group of nuclear receptors which is expressed in the trophoblast and together with other factors is responsible for the maintenance of pregnancy. Apart from that PPARγ is also a main factor for macrophage polarization. The aim of this study was to investigate the combined expression pattern and frequency of PPARγ under physiological circumstances and in spontaneous and recurrent miscarriages in the trophoblast and in maternal macrophages of the decidua. Human placental tissues of the first trimester (15 physiologic pregnancies, 15 spontaneous abortion and 16 recurrent miscarriage placentas) were analyzed for expression of the nuclear receptor PPARγ. Expression changes were evaluated by immunohistochemistry and real time PCR (RT-PCR) in trophoblast and in maternal macrophages of the decidua. Maternal macrophages were identified by double immunofluorescence using cluster of differentiation 68 (CD68) as marker for macrophages and further characterized regarding their M1/M2 polarization status. The intermediate villous trophoblast revealed a significantly lower PPARγ expression in spontaneous and recurrent abortion. Maternal macrophages express PPARγ. Their number is significantly enhanced in the decidua of spontaneous miscarriages whereas in recurrent miscarriages maternal macrophages seem to express PPARγ only in very few cases. PPARγ is associated with an M2 polarization state that is common for decidual macrophages. The lack of PPARγ in recurrent miscarriage decidual macrophages seems to be associated with a specific inflammatory response against the fetus.

Metabolomic Profiling of Plasma Samples from Women with Recurrent Spontaneous Abortion

Background

Gas chromatography coupled with mass spectrometry (GC-MS) and liquid chromatography coupled with mass spectrometry (LC-MS) metabolomics have been deployed to detect novel differential metabolites in cases with recurrent spontaneous abortion (RSA).

Material/Methods

Fifty patients who had recurrent spontaneous abortions (RSAs) and 51 control patients (age, gestational age, and body mass index (BMI) match) were enrolled in this study. Untargeted GC-MS and targeted LC-MS were combined to discover and validate the different metabolomic profiles between groups. Score plots of orthogonal partial least-squares discriminant analysis (OPLS-DA) clearly separated the RSA group from the control group. The variable importance in projection (VIP) generated in OPLS-DA processing represented the contribution to the discrimination of each metabolite ion between groups. Variables with a VIP >1 and P<0.05 were considered to be different variables. We also used MetaboAnalyst 3.0 to analyze the pathway impact of potential metabolite biomarkers.

Results

Fifty-four metabolites were significantly different between the two groups, as indicated by a VIP >1 and P<0.05. The metabolic pathways involving glycine, serine, threonine (P=0.00529, impact=0.26), beta-alanine (P=0.0284, impact=0.27), and phenylalanine metabolism (P=0.0217, impact=0.17), along with the tricarboxylic acid (TCA) cycle (P=0.0113, impact=0.19) and the glycolysis pathway (P=0.037, impact=0.1) are obviously related to RSA. Verification by LC-MS showed that the concentration of lactic acid in RSA was higher than that in the control group (P<0.05), while the concentration of 5-methoxytryptamine was significantly lower in the RSA group (P<0.05).

Conclusions

In our study, untargeted GC-MS was used to detect disturbance of metabolism occurs in RSA and targeted LC-MS further was used to show that plasma concentrations of two metabolites (lactic acid and 5-methoxytryptamine) were different in the RSA compared to the control group.

Genetic variation in the CLOCK gene is associated with idiopathic recurrent spontaneous abortion

Physiological studies in animals and human support an important role of circadian system in reproduction. The aim of this study was to investigate the potential association of CLOCK gene polymorphisms with idiopathic recurrent spontaneous abortion (IRSA). We performed a case-control study. The study group consisted of 268 women with a history of three or more idiopathic recurrent spontaneous abortions and 284 women with at least two live births and no history of pathologic pregnancies all from Slovenia and Serbia. Two SNPs in the CLOCK gene were chosen and genotyped. The results showed a statistically significant difference in genotype distribution between the two groups in the CLOCK gene for rs6850524 and rs11932595. Our analysis showed that G allele under dominant model (GG+GC/CC) for rs6850524 (p = 2∙10-4, OR = 2.28, 95%CI = 1.46-3.56) as well as G allele under dominant model (GA+AA/AA) for rs11932595 (p = 0.04, OR = 1.47, 95%CI = 1.01-2.04) might be risk factors against IRSA. Our data suggest that genetic variability in the CLOCK gene is associated with IRSA warranting further confirmation and mechanistic investigations.

The -2549 insertion/deletion polymorphism in the promoter region of VEGF is associated with the risk of recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a common health problem affecting women of reproductive age. Altered expression of vascular endothelial growth factor (VEGF) has been associated with spontaneous abortion. The present case-control study aimed to evaluate the impact of the 18-bp insertion/deletion (ins/del) polymorphism (rs35569394) in the promoter region of the VEGF gene on idiopathic RSA. Genomic DNA from 93 patients with RSA and 93 healthy fertile women of southeastern Iran was isolated using the salting-out method. Genotyping of the rs35569394 variant was performed by a polymerase chain reaction (PCR) method. The findings indicated that the VEGF 18-bp ins/del variant significantly increased the risk of RSA under codominant (ins/ins vs. del/del; OR=2.85, 95% CI=1.31-6.22, P=0.019), dominant (del/ins+ins/ins vs. del/del; OR=2.19, 95% CI=1.20-4.01, P=0.015) and allelic (ins vs. del; OR=1.90, 95% CI=1.25-2.88, P=0.003) inheritance models. In summary, the findings propose a significant association between the VEGF 18-bp ins/del polymorphism and risk of RSA in a sample of the southeast Iranian population. Further studies on larger sample sizes and different ethnicities are required to validate the present findings.