Epidemiology of recurrent spontaneous abortion

Gut microbiota-derived metabolites associate with circulating immune cell subsets in unexplained recurrent spontaneous abortion

Currently, the precise causes of over 40 % of recurrent spontaneous abortion (RSA) cases cannot be identified, leading to the term "unexplained RSA" (URSA). Through an exploration of the gut microbiota, metabolites, and immune cell subsets in URSA, this study establishes a link between gut microbiota-derived metabolites and immune cells. The results indicate reduced diversity in the gut microbiota of URSA. Targeted metabolomic analyses reveal decreased levels of gut microbiota-derived deoxycholic acid (DCA), glycolithocholic acid (GLCA), acetate, propionate, and butyrate in URSA. Furthermore, elevated frequencies of Th1, Th17, and plasma B cells, along with decreased frequencies of Tregs and Bregs, are observed in the peripheral blood of URSA. The results demonstrate correlations between the levels of gut microbiota-derived bile acids and short-chain fatty acids and the frequencies of various immune cell subsets in circulation. Collectively, this study uncovers an association between gut microbiota-derived metabolites and circulating immune cell subsets in URSA.

Toxicity of Bisphenol in Pregnant Females: First Review of Literature in Humans

Bisphenol analogues are widely used in consumer products such as disposable dinnerware, canned food, personal care products, bottled beverages, and more, and dietary exposure is the main pathway. Bisphenol A is used to manufacture synthetic resins and commercial plastics in large quantities. According to epidemiological and animal studies, bisphenols disrupt the reproductive, immunological, and metabolic systems. These analogues are estrogenic like Bisphenol A, although human studies are limited. We did a thorough search of the literature on the toxicity of bisphenol on reproductive and endocrine systems in pregnancy, focusing particularly on human studies. Hence, we present a comprehensive literature review on this topic.​​​​​​​ During our literature search, three epidemiological studies and one human observational study demonstrated a substantial link between bisphenol toxicity and recurrent miscarriages.​​​​​​​ The aforementioned research shows that bisphenol may harm pregnancy and cause miscarriages. We believe this is the first literature review on the topic.

Impact of maternal depression and anxiety-related disorders on live birth rate in women with recurrent pregnancy loss

It is unknown whether depression and anxiety-related conditions associate with poor perinatal outcomes, especially live birth rates, among women diagnosed with recurrent pregnancy loss. We performed a retrospective cohort study using the Japanese Medical Data Centre Claims Database and identified women diagnosed with recurrent pregnancy loss. Live birth rates were compared as the primary outcome between patients with and without depression and/or anxiety-related disorders. A stabilised inverse probability of treatment weight analysis using propensity scores was also performed to assess the association. Among 5,517 eligible patients, there were 804 (14.6%) women who had depression and/or anxiety-related disorders during treatment for recurrent pregnancy loss during pregnancy. The overall live birth rates differed significantly between the groups according to the Kaplan-Meier method and log-rank test (p = 0.011). However, Cox proportional-hazards regression model and stabilised inverse probability of treatment weight analysis showed no statistically significant association between depressive disorders and live birth rates. The current study showed that approximately 15% of patients diagnosed with recurrent pregnancy loss develop depressive disorders. After accounting for variables, we found no independent association between depressive disorders after recurrent pregnancy losses and low live birth rates.

The haplotypes GCA and ACA in ESR1 gene are associated with the susceptibility of recurrent spontaneous abortion (RSA) in Chinese Han: A case-control study and meta-analysis

The nonstructured abstract were supplied as following: Estrogen receptor is involved in the pathogenesis of recurrent spontaneous abortion (RSA). The ESR1 and ESR2 genes can mediate nongenomic estrogen responses. This study aimed to assess the genetic association between the ESR1 and ESR2 genes polymorphisms and RSA susceptibility in a Chinese Han population. A total of 258 women who had experienced RSA and 264 unrelated healthy women were recruited. Genotypes of the 6 polymorphisms in the ESR1 (rs9340799, rs2234693, and rs3798759) and ESR2 genes (rs207764, rs4986938, and rs1256049) were analyzed using Snapshot technology. No association was detected between the alleles and genotypes of ESR1 rs9340799, rs2234693, and rs3798759 polymorphims and RSA risk (P > .05). Subjects carrying the haplotype of rs9340799A-rs2234693C-rs3798759A had a significantly increased RSA risk in the case group compared with the control group (P = .0005, Padj = .003, odds ratios [95% CI] = 0.35 [0.19-0.65]). However, subjects carrying the haplotype of rs9340799G-rs2234693C-rs3798759A had a significantly decreased RSA risk in the case group compared with the control group (P = .0005, Padj = .003, odds ratios [95% CI] = 2.99 [1.57-5.70]). In addition, no association was found between the alleles, genotypes, and haplotypes of ESR2 rs207764, rs4986938, rs1256049 polymorphisms and RSA risk (P > .05). In conclusion, the haplotype rs9340799A-rs2234693C-rs3798759A of ESR1 might be a risk factor. And the haplotype rs9340799G-rs2234693C-rs3798759A of ESR1 might be a protective factor for RSA in a Chinese Han population.

Environmental exposure to bisphenol analogues and unexplained recurrent miscarriage: A case-control study

The use of bisphenol A (BPA) has been substantially limited since 2010 due to its toxicity to human health. A group of bisphenol analogues that are structurally similar to BPA have been developed as the alternatives and used widely. The reproductive toxicity of these emerging chemicals has caused substantial concerns in recent years. Whether bisphenol analogues affect miscarriage, especially unexplained recurrent miscarriage (URM), remains to be explored. We conducted a hospital-based, case-control study with 1180 URM cases and 571 controls in China from 2014 to 2016. Concentrations of six bisphenol analogues (BPA, BPAF, BPAP, BPB, BPP and BPS) were measured in the urine samples collected at median intervals of 7.6 months after last miscarriage (interquartile ranges: 4.8, 14.7 months). Multiple logistic regression, Bayesian kernel machine regression (BKMR) and quantile g-computation (q-gcomp) were used to assess the relationship of bisphenol analogues with URM risk. We observed significantly higher levels of all urinary bisphenols in the cases than the controls. After controlling for potential confounders, bisphenol analogues were significantly associated with increased odds of URM in varying degrees. A dose-response pattern was observed for the associations of BPAF, BPAP and BPB quartiles with URM. The mixed exposure of six bisphenol analogues was positively associated with the risk of URM (adjusted odds ratio (aOR) = 1.25; 1.11-1.42), which was mainly driven by BPAP (60.1%), BPAF (25.1%) and BPA (14.8%). After age stratification, the risks tended to be higher in women aged 30 years or older, compared to women <30 years. Our large case-control study indicates that environmental exposure to bisphenol analogues is associated with an increased risk of URM. Older women may be more vulnerable to the insult.

Cytogenetic Studies of 608 Couples with Recurrent Spontaneous Abortions in Northeastern Iran

Background & Objective:

One of the major genetic causes of recurrent spontaneous abortions is parental chromosomal abnormalities. The objectives of the study were to determine, compare and analyze the incidence and distribution of chromosomal abnormalities in couples with recurrent miscarriages from Northeastern Iran.

Methods:

This study was conducted at Ghaem Hospital, Mashhad, Iran. We evaluated karyotype results of 608 couples with history of recurrent spontaneous abortion. The standard method was used for culturing peripheral venous blood lymphocytes.

Results:

Chromosome aberrations were detected in 43 patients (3.54%), including 25 females and 18 males. Structural chromosomal abnormality was detected in 40 cases, including balanced translocations (25 cases), robertsonian translocations (4 cases), inversions (10 cases) and numerical chromosome aberrations (3 cases). Polymorphic variants were observed in 22 individuals.

Conclusion:

The frequency of chromosomal abnormalities in couples with Recurrent Spontaneous Abortion (RSA) in our study is 3.54%. Reciprocal translocation, pericentric inversions, robertsonian translocations, and numerical abnormality observed among couples who had experienced recurrent spontaneous abortions and that these couples might benefit from cytogenetic analysis.

Evaluation of paternal lymphocyte immunotherapy and potential biomarker mixed lymphocyte reaction-blocking factor in an Argentinian cohort of women with unexplained recurrent spontaneous abortion and unexplained infertility

PROBLEM

Analyze the effect of paternal immunotherapy treatment (PIT) in primary and secondary unexplained recurrent spontaneous abortion (URSA) and unexplained infertility (UI).

METHODS OF STUDY

A retrospective study analyzed a two-year follow-up between the generation of MLR-Bfs after PIT treatment (or controls first consultation) and a live birth. Recruited patients included primary URSA with two or more miscarriages at <12 weeks gestation, secondary URSA with previous live birth before two or more miscarriages, and UI with inability to conceive after 2 years of regular unprotected intercourse or in vitro fertilizations (IVF). PIT treated were compared with untreated controls.

RESULTS

Primary URSA: live birth was 241/416 (58%) versus 64/282 (23%) controls (p < .0001). Up to age 35, success was 158/217 (73%) and 37/144 (26%) controls (p < .0001). With 3 or more previous URSA, success was 90/135 (67%) versus 17/79 (22%) controls (p < .0001). Between ages 36 and 40, success was 69/147(47%) versus 22/98 (22%) controls (p < .0003), with 3 or more previous URSA live birth was 45/95 (47%) versus 6/46 (13%) controls (p < .0001). In UI, live birth was 99/298 (33%) versus 54/263 (21%) in controls (p < .0009) that increased under age 35 to 53/116 (46%) in treated versus 26/101 (26%) controls (p < .0056). In PIT treated, IVF success required a median of 1 (1.37 ± 0.67) versus a median of 3 IVF procedures (2.75 ± 0.84) in controls.

CONCLUSION

PIT is a successful treatment for primary and secondary URSA, and UI. PIT reduced the number of IVF required for achieving pregnancy.

Effect of Japanese herbal Kampo medicines on live birth rate in women with recurrent pregnancy loss

OBJECTIVE

To determine the effectiveness of Japanese Kampo medicines on the overall live birth rate among patients with recurrent pregnancy loss (RPL) in a real-world setting.

METHODS

In the current retrospective cohort study, we used the JMDC Claims Database to extract information on women diagnosed with RPL between January 1, 2005 and August 31, 2018. Eligible women were divided into two groups according to Kampo medicines administered as treatments for RPL. The primary outcome was the live birth rate during the study period. Propensity score matching, Kaplan-Meier cumulative incidence plots, log-rank test, and Cox proportional-hazards regression model were used to compare the primary outcome between patients with and without Japanese herbal Kampo medicines.

RESULTS

Among 5517 eligible patients, 1652 used Kampo medicines and 3865 did not. After propensity score matching, the live birth rate at 2.0 years was 15.7% in the Kampo group and 11.2% in the non-Kampo group. At 4.0 years, the difference between the two groups had slightly increased. The overall live birth rate differed significantly between the two groups (hazard ratio 1.32, 95% confidence interval 1.13-1.53; P < 0.001).

CONCLUSION

Japanese herbal Kampo medicines may improve the live birth rate in patients with RPL.

Cytogenetic Analysis of 570 Couples with Recurrent Pregnancy Loss: Reporting 11 Years of Experience

Objectives

Recurrent pregnancy loss (RPL) is a serious complication of pregnancies, affecting almost 2%-5% of couples. Among numerous underlying causes, chromosomal anomalies in one of the partners are regarded as important issues, with varying frequencies among different populations. In this study, we aimed to determine the prevalence of chromosomal abnormalities and chromosome polymorphisms in couples with a history of RPL from Kermanshah province, west of Iran.

Materials and Methods

In this 11-year retrospective study, a total of 1140 cases with two or more spontaneous abortions were recruited and studied according to standard cytogenetic analysis.

Results

From a total of 1140 reviewed blood samples, 1011 people (88.5%) had a normal karyotype and 129 people (11.5%) had chromosomal aberrations. These aberrations were found in 62 females and 67 males. The prevalence of chromosomal abnormalities was as follows: 18 (1.5%) structural aberrations, 1 numerical anomaly and 110 (9.6%) apparently normal polymorphic variants.

Conclusions

Our findings could determine the underlying cause of RPL in 1.5% of the population while the majority still remained unexplained. This emphasizes the importance of searching for other genetic and nongenetic causes of RPL in apparently idiopathic cases of RPL.

ATP6V1G3 Acts as a Key Gene in Recurrent Spontaneous Abortion: An Integrated Bioinformatics Analysis

BACKGROUND The molecular mechanism of recurrent spontaneous abortion is unclear. It has been suggested that dysregulated genes participate in the pathogenesis of recurrent spontaneous abortion. The aim of this study was to identify the differentially expressed genes (DEGs) and pathways in recurrent spontaneous abortion. MATERIAL AND METHODS Gene expression data series of GSE22490 and GSE26787 were obtained from the GEO database to identify the differentially expressed genes between patients with recurrent miscarriage (Case group) and patients with uncomplicated pregnancies matched for gestational age (Control group). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEEG) were applied to enrich the biological functions and pathways of the identified differentially expressed genes. A protein-protein interaction (PPI) network was constructed thorough the STRING database. Thirty-one cases of recurrent spontaneous abortion (Case group) and 30 cases of artificial abortion (Control group) were included in the study. The protein expression of hub genes in the villi and decidua tissue of the 2 groups was detected by immunohistochemical assay. RESULTS Forty-six DEGs were identified with the enriched biological function mainly in the aspects of glutamate secretion and positive regulation of synapse assembly. KEGG pathway analysis indicated the dysregulated genes were only enriched in the glutamatergic synapse pathway. In the PPI network, 83 nodes and 273 edges with the average node degreed of 6.58 were enriched. The hub gene (ATP6V1G3) of the included 46 genes was identified using Cytohubba software. In the Case group, the high expression of ATP6V1G3 protein was detected in 13 (43.3%) and 10 (33.3%) for placental villus and decidual tissue, respectively. However, the high expression rate in the Control group was 23.3% and 16.7% for placental villus and decidual tissue, respectively. The ATP6V1G3 protein high expression rate was not significantly different between the Case and Control groups (P>0.05). CONCLUSIONS We found differential gene expression profiles in villous and decidual tissues between patients with recurrent miscarriage vs. those with uncomplicated pregnancies. Upregulation of the ATP6V1G3 gene may play an important role in the development of recurrent miscarriage.

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.

Progestogen for preventing miscarriage in women with recurrent miscarriage of unclear etiology

BACKGROUND

Progesterone, a female sex hormone, is known to induce secretory changes in the lining of the uterus essential for successful implantation of a fertilized egg. It has been suggested that a causative factor in many cases of miscarriage may be inadequate secretion of progesterone. Therefore, clinicians use progestogens (drugs that interact with the progesterone receptors), beginning in the first trimester of pregnancy, in an attempt to prevent spontaneous miscarriage. This is an update of a review, last published in 2013. Since publication of the 2018 update of this review, we have been advised that the Ismail 2017 study is currently the subject of an investigation by the Journal of Maternal-Fetal & Neonatal Medicine. We have now moved this study from 'included studies' to 'Characteristics of studies awaiting classification' until the outcome of the investigation is known.

OBJECTIVES

To assess the efficacy and safety of progestogens as a preventative therapy against recurrent miscarriage.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (6 July 2017) and reference lists from relevant articles, attempting to contact trial authors where necessary, and contacted experts in the field for unpublished works.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing progestogens with placebo or no treatment given in an effort to prevent miscarriage.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Two reviewers assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

Twelve trials (1,856 women) met the inclusion criteria. Eight of the included trials compared treatment with placebo and the remaining four trials compared progestogen administration with no treatment. The trials were a mix of multicenter and single-center trials, conducted in India, Jordan, UK and USA. In five trials women had had three or more consecutive miscarriages and in seven trials women had suffered two or more consecutive miscarriages. Routes, dosage and duration of progestogen treatment varied across the trials. The majority of trials were at low risk of bias for most domains. Ten trials (1684 women) contributed data to the analyses. The meta-analysis of all women, suggests that there may be a reduction in the number of miscarriages for women given progestogen supplementation compared to placebo/controls (average risk ratio (RR) 0.73, 95% confidence interval (CI) 0.54 to 1.00, 10 trials, 1684 women, moderate-quality evidence). A subgroup analysis comparing placebo-controlled versus non-placebo-controlled trials, trials of women with three or more prior miscarriages compared to women with two or more miscarriages and different routes of administration showed no clear differences between subgroups for miscarriage. None of the trials reported on any secondary maternal outcomes, including severity of morning sickness, thromboembolic events, depression, admission to a special care unit, or subsequent fertility. There was probably a slight benefit for women receiving progestogen seen in the outcome of live birth rate (RR 1.07, 95% CI 1.00 to 1.13, 6 trials, 1411 women, moderate-quality evidence). We are uncertain about the effect on the rate of preterm birth because the evidence is very low-quality (RR 1.13, 95% CI 0.53 to 2.41, 4 trials, 256 women, very low-quality evidence). No clear differences were seen for women receiving progestogen for the other secondary outcomes including neonatal death, fetal genital abnormalities or stillbirth. There may be little or no difference in the rate of low birthweight and trials did not report on the secondary child outcomes of teratogenic effects or admission to a special care unit.

AUTHORS' CONCLUSIONS

For women with unexplained recurrent miscarriages, supplementation with progestogen therapy may reduce the rate of miscarriage in subsequent pregnancies.

Oral sex is associated with reduced incidence of recurrent miscarriage

A possible way of immunomodulation of the maternal immune system before pregnancy would be exposure to paternal antigens via seminal fluid to oral mucosa. We hypothesized that women with recurrent miscarriage have had less oral sex compared to women with uneventful pregnancy. In a matched case control study, 97 women with at least three unexplained consecutive miscarriages prior to the 20^th week of gestation with the same partner were included. Cases were younger than 36 years at time of the third miscarriage. The control group included 137 matched women with an uneventful pregnancy. The association between oral sex and recurrent miscarriage was assessed with conditional logistic regression, odds ratios (ORs) were estimated. Missing data were imputed using Imputation by Chained Equations. In the matched analysis, 41 out of 72 women with recurrent miscarriage had have oral sex, whereas 70 out of 96 matched controls answered positive to this question (56.9% vs. 72.9%, OR 0.50 95%CI 0.25-0.97, p = 0.04). After imputation of missing exposure data (51.7%), the association became weaker (OR 0.67, 95%CI 0.36-1.24, p = 0.21). In conclusion, this study suggests a possible protective role of oral sex in the occurrence of recurrent miscarriage in a proportion of the cases. Future studies in women with recurrent miscarriage explained by immune abnormalities should reveal whether oral exposure to seminal plasma indeed modifies the maternal immune system, resulting in more live births.

The Study of HLA-G Gene and Protein Expression in Patients with Recurrent Miscarriage

Purpose: Although it has been frequently confirmed that HLA-G plays an important role in the reproduction and pregnancy, the pattern of HLA-G gene and its protein expression are rarely addressed in studies. Therefore we conducted this study in regard to evaluate the HLA-G gene and its protein expression in the women’s placenta with recurrent miscarriage.

Methods: Placental samples were obtained from the women who were admitted for delivery or abortion in Al Zahra and Taleghani hospitals, Tabriz, Iran. HLA-G gene expression was determined by real-time polymerase chain reaction (PCR) and HLA-G protein expression was assessed by western blotting and immunofluorescence staining in the tissue samples.

Results: The results showed a significant decrease in the expression of gene and proteins of HLA-G in the women with recurrent miscarriage compared to the control placental tissues.

Conclusion: According to the obtained results, it was concluded that the decrement of HLA-G gene and protein expressions are associated with recurrent miscarriage. Since there are conflicting results from other studies, it is suggested to conduct a more comprehensive similar study with greater sample size.

Effect of multiple thrombophilic gene mutations on uterine artery blood flow in nonpregnant recurrent pregnancy loss patients: are we searching enough?

Objective: To investigate whether multiple thrombophilic mutations had a significant effect on uterine artery blood flow of nonpregnant recurrent pregnancy loss (RPL) patients.Materials and methods: Among 71 RPL patients, FV Leiden (FV), prothrombin G20210A (PTGM) and MTHFR mutations, deficiency of protein S, protein C and antithrombin III (AT3), association of Val34Leu polymorphism of the FXIII (FXIII), 4G/5G polymorphism of plasminogen activator inhibitor (PAI), -455-G/A polymorphism of β-fibrinogen (fibrinogen), and HPA-1 a/b L33P polymorphism of GPIIIa (GPIIIa) genes were investigated. Doppler flow measurements of RPL patients and healthy controls were performed at mid-luteal phase.Results: Twenty-two patients who had no thrombophilic gene mutations were grouped as unexplained RPL. Also, while 25 patients had multiple mutations, 24 patients had single mutation. In the multiple mutation RPL group, the most frequent mutations were PAI (22%), MTHFR C677T (20%), MTHFR A1298C (19%), and fibrinogen (11%). Only in the multiple mutation RPL group, mean PI and dominant PI values were significantly higher than the control group.Conclusions: Our data showed negative effects of multiple thrombophilic gene mutations on uterine artery blood flow and clarified the different effects of single and multiple thrombophilic factors on uterine artery vasculature. It is concluded that investigating more thrombophilic mutations could ameliorate prognostic factors of RPL and interactions to improve uterine artery blood flow could bring benefit to obstetric outcome.

Connecting links between genetic factors defining ovarian reserve and recurrent miscarriages

PURPOSE

Approximately 1-2% of the women faces three or more successive spontaneous miscarriages termed as recurrent miscarriage (RM). Many clinical factors have been attributed so far to be the potential risk factors in RM, including uterine anomalies, antiphospholipid syndrome, endocrinological abnormalities, chromosomal abnormalities, and infections. However, in spite of extensive studies, reviews, and array of causes known to be associated with RM, about 50% cases encountered by treating physicians remains unknown. The aims of this study were to evaluate recent publications and to explore oocyte-specific genetic factors that may have role in incidence of recurrent miscarriages.

METHOD

Recent studies have identified common molecular factors contributing both in establishment of ovarian reserve and in early embryonic development. Also, studies have pointed out the relationship between the age-associated depletion of OR and increase in the risk of miscarriages, thus suggestive of an interacting biology. Here, we have gathered literature evidences in establishing connecting links between genetic factors associated with age induced or pathological OR depletion and idiopathic RM, which are the two extreme ends of female reproductive pathology.

CONCLUSION

In light of connecting etiological link between infertility and RM as reviewed in this study, interrogating the oocyte-specific genes with suspected roles in reproductive biology, in cases of unexplained RM, may open new possibilities in widening our understanding of RM pathophysiology.

Chromosomal abnormalities in couples with recurrent spontaneous miscarriage: a 21-year retrospective study, a report of a novel insertion, and a literature review

PURPOSE

The aim of this study is to evaluate the frequency and nature of chromosomal abnormalities in Moroccan couples with recurrent spontaneous miscarriage (RSM). In addition, the data were compared with those reported elsewhere in order to give a global estimation of chromosomal abnormalities frequencies.

METHODS

The study was performed for all couples with RSM who were referred to the cytogenetic department, Pasteur Institute of Morocco, from different hospitals in Morocco between 1996 and 2016. Cytogenetic analysis was performed according to the standard method.

RESULTS

Among 627 couples with RSM, the chromosomal abnormalities were identified in 11.00% of couples, with chromosomal inversions in 4.30%, reciprocal translocations in 2.71%, Robertsonian translocations in 1.43%, and deletion, isochromosome, and insertion in 0.15% each. The insertion identified [46,XX,ins(6)(p24q21q27)] is new, and is the fourth reported in association with RSM. The mosaic karyotypes were observed in 0.64%, polymorphic variants were identified in 1.27%, and numerical aneuploidy was observed in 0.15%. In regrouping our results with those in 27 other studies already published in 21 different countries, we obtained the frequency of chromosomal abnormalities in couple with RSM to be 5.16% (991/19197 couples). The reciprocal translocation was the most frequent with 2.50%, followed by Robertsonian translocation 0.83% and inversions 0.77%. The other types of chromosomal abnormalities were present with 0.98% in the world.

CONCLUSION

This data showed that the frequency of chromosomal abnormalities in Moroccan couples with RSM is 11.00%, and in regrouping our results with other studies, the frequency changes to 5.16%.

Causative Mutations and Mechanism of Androgenetic Hydatidiform Moles

Androgenetic complete hydatidiform moles are human pregnancies with no embryos and affect 1 in every 1,400 pregnancies. They have mostly androgenetic monospermic genomes with all the chromosomes originating from a haploid sperm and no maternal chromosomes. Androgenetic complete hydatidiform moles were described in 1977, but how they occur has remained an open question. We identified bi-allelic deleterious mutations in MEI1, TOP6BL/C11orf80, and REC114, with roles in meiotic double-strand breaks formation in women with recurrent androgenetic complete hydatidiform moles. We investigated the occurrence of androgenesis in Mei1-deficient female mice and discovered that 8% of their oocytes lose all their chromosomes by extruding them with the spindles into the first polar body. We demonstrate that Mei1^-/- oocytes are capable of fertilization and 5% produce androgenetic zygotes. Thus, we uncover a meiotic abnormality in mammals and a mechanism for the genesis of androgenetic zygotes that is the extrusion of all maternal chromosomes and their spindles into the first polar body.

Progestogen for preventing miscarriage in women with recurrent miscarriage of unclear etiology

BACKGROUND

Progesterone, a female sex hormone, is known to induce secretory changes in the lining of the uterus essential for successful implantation of a fertilized egg. It has been suggested that a causative factor in many cases of miscarriage may be inadequate secretion of progesterone. Therefore, clinicians use progestogens (drugs that interact with the progesterone receptors), beginning in the first trimester of pregnancy, in an attempt to prevent spontaneous miscarriage. This is an update of a review, last published in 2013.

OBJECTIVES

To assess the efficacy and safety of progestogens as a preventative therapy against recurrent miscarriage.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (6 July 2017) and reference lists from relevant articles, attempting to contact trial authors where necessary, and contacted experts in the field for unpublished works.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing progestogens with placebo or no treatment given in an effort to prevent miscarriage.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. Two reviewers assessed the quality of the evidence using the GRADE approach.

MAIN RESULTS

Thirteen trials (2556 women) met the inclusion criteria. Nine of the included trials compared treatment with placebo and the remaining four trials compared progestogen administration with no treatment. The trials were a mix of multicenter and single-center trials, conducted in Egypt, India, Jordan, UK and USA. In six trials women had had three or more consecutive miscarriages and in seven trials women had suffered two or more consecutive miscarriages. Routes, dosage and duration of progestogen treatment varied across the trials. The majority of trials were at low risk of bias for most domains. Eleven trials (2359 women) contributed data to the analyses.The meta-analysis of all women, suggests that there is probably a reduction in the number of miscarriages for women given progestogen supplementation compared to placebo/controls (average risk ratio (RR) 0.69, 95% confidence interval (CI) 0.51 to 0.92, 11 trials, 2359 women, moderate-quality evidence). A subgroup analysis comparing placebo-controlled versus non-placebo-controlled trials and different routes of administration showed no differences between subgroups for miscarriage. However, there appears to be a subgroup difference for miscarriage between women with three or more prior miscarriages compared to women with two or more miscarriages, with a more pronounced effect in women with three or more prior miscarriages. However, it should be noted that there was high heterogeneity in the subgroup of women with three or more prior miscarriages.None of the trials reported on any secondary maternal outcomes, including severity of morning sickness, thromboembolic events, depression, admission to a special care unit, or subsequent fertility.There was probably a slight benefit for women receiving progestogen seen in the outcome of live birth rate (RR 1.11, 95% CI 1.00 to 1.24, 7 trials, 2086 women, moderate-quality evidence). While the rate of preterm birth is probably reduced for women receiving progestogen, this outcome was mainly driven by one trial and thus should be interpreted with great caution (RR 0.59, 95% CI 0.39 to 0.89, 5 trials, 811 women, moderate-quality evidence). No clear differences were seen for women receiving progestogen for the other secondary outcomes of neonatal death or fetal genital abnormalities. A possible reduction in stillbirth was seen, but again this outcome was driven mainly by one trial and should be interpreted with caution (RR 0.38, 95% CI 0.24 to 0.58, 3 trials, 1199 women). There may be little or no difference in the rate of low birthweight and trials did not report on the secondary child outcomes of teratogenic effects or admission to a special care unit.

AUTHORS' CONCLUSIONS

For women with unexplained recurrent miscarriages, supplementation with progestogen therapy probably reduces the rate of miscarriage in subsequent pregnancies.

Fas and FasL genetic polymorphisms in women with recurrent pregnancy loss: a case-control study

Aberrant apoptosis at the trophoblast-maternal interface and abnormal expression of Fas and Fas ligand (FasL) have been reported in complicated pregnancies with recurrent pregnancy losses (RPL) and preeclampsia. We assessed the prevalence of Fas and FasL genetic polymorphisms in Korean women with RPL and in fertile controls. In total, 306 women with RPL and 298 fertile controls were enrolled. Genotype distributions of Fas and FasL in RPL patients versus fertile controls were examined under the Hardy-Weinberg equilibrium. Fas -670 A/G genotype (AA versus AG versus GG, p = 0.340) and allele frequencies (A versus G, p = 0.412) were not different between the RPL and control groups. There was no difference in each Fas -1377 G/A and FasL -844 C/T genotype, and their allele frequencies. In addition, the unions of two zygosities of each genotype and their combined genotypes did not differ between two groups. No difference in the prevalence of Fas and FasL single-nucleotide polymorphisms (SNPs) was observed between women with RPL and fertile controls among Korean women. To determine the possibility of genetic polymorphisms in Fas and its ligand as risk factors for RPL, further studies in various races and a large study population are needed.

Paternal HLA-C is a risk factor in unexplained recurrent miscarriage

PROBLEM

HLA-C is the only classical HLA-I antigen expressed on trophoblast. We hypothesized that the alloimmune response to paternal HLA-C plays a role in unexplained recurrent miscarriage.

METHOD OF STUDY

In a case-control design, we included 100 women with at least three unexplained consecutive miscarriages along with their partners and children. For the first control group, we included 90 women with an uneventful singleton pregnancy without pregnancy complications in their history along with their children. The second control group consisted of 425 families. HLA-C*07 and HLA-C*17 frequencies, which are the most immunogenic HLA-C antigens, along with HLA-C mismatches, and the presence of specific HLA antibodies in the mother were determined.

RESULTS

HLA-C and HLA-C*07 mismatches were significantly increased in couples with recurrent miscarriage compared to control subjects (P = .016, P = .008, respectively). The incidence of child-specific HLA-C*07/HLA-C*17 antibodies was increased in women with recurrent miscarriage (P = .007).

CONCLUSION

The results show that HLA-C incompatibility between couples is significantly associated with unexplained recurrent miscarriage.

Cytogenetic analysis in couples with recurrent miscarriages: a retrospective study from Punjab, north India

Human reproduction is considered as the most inefficient event as ~15-20% of human pregnancies end in miscarriage and in the product of miscarriages, chromosomal anomalies are a common occurrence. The aim of the present retrospective study was to assess the frequency of chromosomal aberrations in couples with recurrent miscarriages in the region of Punjab and to compare with worldwide frequencies. In this study, a total of 440 cases were referred between the period 1995-2015. After lymphocyte culturing, giemsa-trypsin banding was done for each case to assess the chromosomal anomalies. The frequency of chromosomal aberrations among couples was found to be 3.41% in our study. Among these aberrations, balanced reciprocal translocations formed the largest group with 60% anomalies. We would conclude that clinicians should understand the importance of chromosomal analysis in these couples and refer them for karyotyping after two miscarriages to rule out the possible genetic cause of recurrent miscarriages.

HLA-C antibodies in women with recurrent miscarriage suggests that antibody mediated rejection is one of the mechanisms leading to recurrent miscarriage

HLA-C is the only polymorphic classical HLA I antigen expressed on trophoblast cells. It is known that higher incidence of C4d deposition on trophoblast cells is present in women with recurrent miscarriage. C4d is a footprint of antibody-mediated classical complement activation. Therefore, this study hypothesize that antibodies against HLA-C may play a role in the occurrence of unexplained consecutive recurrent miscarriage. Present case control study compared the incidence of HLA-C specific antibodies in 95 women with at least three consecutive miscarriages and 105 women with uneventful pregnancy. In the first trimester of the next pregnancy, presence and specificity of HLA antibodies were determined and their complement fixing ability. The incidence of HLA antibodies was compared with uni- and multivariate logistic regression models adjusting for possible confounders. Although in general a higher incidence of HLA antibodies was found in women with recurrent miscarriage 31.6% vs. in control subjects 9.5% (adjusted OR 4.3, 95% CI 2.0-9.5), the contribution of antibodies against HLA-C was significantly higher in women with recurrent miscarriage (9.5%) compared to women with uneventful pregnancy (1%) (adjusted OR 11.0, 95% CI 1.3-89.0). In contrast to the control group, HLA-C antibodies in the recurrent miscarriage group were more often able to bind complement. The higher incidence of antibodies specific for HLA-C in women with recurrent miscarriage suggests that HLA-C antibodies may be involved in the aetiology of unexplained consecutive recurrent miscarriage.

Chromosomal analyses of 1510 couples who have experienced recurrent spontaneous abortions

In this retrospective study, karyotype results of 1510 couples with a history of recurrent spontaneous abortion were evaluated. The study was conducted at Balcalı Hospital in Adana region of Turkey. For all cases, peripheral blood lymphocytes were cultured for chromosome study using the standard method. Chromosome aberrations were detected in 62 couples (4.1% of all couples). At an individual level, chromosome aberrations were found in a total of 65 cases (41 females and 24 male cases), with structural chromosomal aberrations in 58 cases including balanced translocations in 30 cases, Robertsonian translocations in 12 cases, deletions in seven cases, inversions in nine cases and numerical chromosome aberrations in seven cases. The results of the study indicated that structural aberrations, particularly translocations, were the most common type of aberration observed among couples who had experienced recurrent spontaneous abortions and that these couples might benefit from cytogenetic analyses.

HLA associations and HLA sharing in recurrent miscarriage: A systematic review and meta-analysis

PROBLEM

The aim of this meta-analysis was to evaluate whether specific maternal HLA alleles and HLA sharing of couples are associated with the occurrence of recurrent miscarriage (RM).

METHOD OF STUDY

A systematic literature search was performed for studies that evaluated the association between HLA alleles, HLA sharing and RM. RM was defined as three or more consecutive unexplained miscarriages and a control group was included of women with at least one live birth and no miscarriages in their history. Meta-analyses were performed and the pooled odds ratio (OR) was calculated.

RESULTS

We included 41 studies. Selection bias was present in 40 studies and information bias in all studies. Meta-analyses showed an increased risk of RM in mothers carrying a HLA-DRB1*4 (OR 1.41, 95% CI 1.05-1.90), HLA-DRB1*15 (OR 1.57, 95% CI 1.15-2.14), or a HLA-E*01:01 allele (OR 1.47, 95% CI 0.20-1.81), and a decreased risk with HLA-DRB1*13 (OR 0.63, 95% CI 0.45-0.89) or HLA-DRB1*14 (OR 0.54, 95% CI 0.31-0.94). Pooling results for HLA sharing showed that HLA-B sharing (OR 1.39, 95% CI 1.11-1.75) and HLA-DR sharing (OR 1.57, 95% CI 1.10-1.25) were both associated with the occurrence of RM.

CONCLUSION

Although the present systematic review and meta-analysis demonstrates that specific HLA alleles and HLA sharing are associated with RM, a high degree of bias was present and therefore observed results should be interpreted carefully.

1(st) trimester miscarriage: four decades of study

Miscarriage is a very common occurrence in humans. This paper sets out to present published data on research that has provided increased understanding of pregnancy failure. Clarification of definitions, exploring the range of failures from preclinical to later pregnancy losses, and the scientific tools employed to find information on the losses have been documented. What is now understood, which tools work best, and the associated limitations are all discussed. Early studies used cytogenetic methods and tissue culture to obtain results. Improvements in laboratory tools such as better tissue culture incubators, inverted microscopes, laminar flow hoods, improvements in culture media, all contributed to obtaining more results for patients. These studies demonstrated the significant contribution of unbalanced chromosomal karyotypes to pregnancy failure. Maternal age as a contributing factor in trisomy was clearly demonstrated. First trimester miscarriage exhibits very high cytogenetic abnormality; in contrast to very low rates in later losses. Combining data across all time periods of pregnancy will affect the significance of chromosomal error in the early pregnancy failures. Cytogenetic methods investigate whole genomes, and are considered to represent the standard against which new methods must be validated. New molecular genetic methods provide the opportunity to examine samples without the necessity of tissue culture. Techniques may be site-specific or whole genome. Fluorescent in situ hybridisation (FISH), comparative genomic hybridisation (CGH), array-based CGH, single nucleotide polymorphism (SNP) detection, quantitative polymerase chain reaction (qPCR), and quantitative fluorescent PCR (QF-PCR), have all been utilised. In comparison studies with classical/conventional cytogenetics, each newer method offers advantages and limitations. At the present time, a combined approach using conventional and molecular methods will elucidate the cause of miscarriage for almost all samples. In a clinical setting this would be optimum.

Gene expression analysis of VEGF and its receptors and assessment of its serum level in unexplained recurrent spontaneous abortion

Objective

Unexplained recurrent spontaneous abortion (URSA) is one of the main complications of pregnancy which is usually defined as three or more consecutive pregnancy losses before the 20^th week of gestation without a known cause. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor and shown, along with its receptors (VEGFR1, 2), to play important roles in several physiologic processes including reproduction. The aim of the present study was to analyze gene expression of VEGF and VEGF receptors in endometrium of patients with a history of URSA compared with normal fertile women. In addition, serum VEGF concentration was assessed and compared between the two groups at the same time.

Materials and Methods

In this case control study, endometrial and blood samples were obtained between day 19^thand 24^th of menstrual cycle (window of implantation) from 10 women with a history of URSA (case group) and 6 fertile women who had at least one successful pregnancy (control group). Expression of VEGF and VEGFRs was studied by reverse transcription- polymerase chain reaction (RT-PCR) and then quantified by real time PCR. Normalization of expression levels was done by comparison with beta-actin expression level as an internal control. Relative VEGF, VEGFR1 and VEGFR2 expression quantities were compared between the two groups. Enzyme linked immunosorbent assay (ELISA) was used for serum VEGF assay.

Results

VEGF, VEGFR1 and VEGFR2 gene expression was detected in endometrial samples of both groups. The mean relative expression of VEGF gene was lower in the case group compared with control women, however, both VEGF receptors were expressed higher in endometrium of the case group. In addition, the serum level of VEGF was significantly higher in the case group compared with the controls.

Conclusion

Alteration in gene expression of VEGF and its receptors in endometrium and changes of serum VEGF might play important roles in pathogenesis of unexplained RSA.

Recurrent spontaneous miscarriage is still a challenging diagnostic and therapeutic quagmire

Recurrent spontaneous miscarriage (RSM), affecting 1-2% of women of reproductive age seeking pregnancy, has been a clinical quagmire and a formidable challenge for the treating physician. There are many areas of controversy in the definition, aetiology, investigations and treatment of RSM. This review will address the many factors involved in the aetiology of RSM which is multifactorial in many patients, with antiphospholipid syndrome (APS) being the most recognized aetiological factor. There is no identifiable cause in about 40-60% of these patients, in which case the condition is classified as idiopathic or unexplained RSM. The RSM investigations are extensive and should be undertaken in dedicated, specialized, well-equipped clinics/centres where services are provided by trained specialists. The challenges faced by the treating physician are even more overwhelming regarding the decision of what should be the most appropriate therapy offered to patients with RSM. Our review will cover the diverse modalities of therapy available including the role of preimplantation genetic testing using recent microarray technology, such as single nucleotide polymorphism and comparative genomic hybridization, as well as preimplantation genetic diagnosis; the greatest emphasis will be on the treatment of APS, and there will be important comments on the management of patients presenting with idiopathic RSM. The controversial areas of the role of natural killer cells in RSM, the varied modalities in the management of idiopathic RSM and the need for better-planned studies will be covered as well.

Uterine factors

Uterine anomalies are one of the most common parental causes of recurrent pregnancy loss, occurring in about 19% of patients. Congenital uterine anomalies are most likely caused by HOX gene mutations, although the mechanism is probably polygenic. There are no known environmental causes other than estrogenic endocrine disruptors such as diethylstilbestrol. Acquired uterine anomalies may result from uterine trauma (adhesions) or benign growths of the myometrium (fibroids) or endometrium (polyps). Although randomized controlled trials are lacking, surgical treatment is recommended for repair of uterine septa, and for removal of severe adhesions and submucosal fibroids, especially if no other causes are identified.

Immunotherapy for recurrent miscarriage

BACKGROUND

Because immunological aberrations might be the cause of miscarriage in some women, several immunotherapies have been used to treat women with otherwise unexplained recurrent pregnancy loss.

OBJECTIVES

The objective of this review was to assess the effects of any immunotherapy, including paternal leukocyte immunization and intravenous immunoglobulin on the live birth rate in women with previous unexplained recurrent miscarriages.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 February 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

Randomized trials of immunotherapies used to treat women with three or more prior miscarriages and no more than one live birth after, in whom all recognized non-immunologic causes of recurrent miscarriage had been ruled out and no simultaneous treatment was given.

DATA COLLECTION AND ANALYSIS

The review author and the two co-authors independently extracted data and assessed study quality for all studies considered for this review.

MAIN RESULTS

Twenty trials of high quality were included. The various forms of immunotherapy did not show significant differences between treatment and control groups in terms of subsequent live births: paternal cell immunization (12 trials, 641 women), Peto odds ratio (Peto OR) 1.23, 95% confidence interval (CI) 0.89 to 1.70; third-party donor cell immunization (three trials, 156 women), Peto OR 1.39, 95% CI 0.68 to 2.82; trophoblast membrane infusion (one trial, 37 women), Peto OR 0.40, 95% CI 0.11 to 1.45; or intravenous immunoglobulin, (eight trials, 303 women), Peto OR 0.98, 95% CI 0.61 to 1.58.

AUTHORS' CONCLUSIONS

Paternal cell immunization, third-party donor leukocytes, trophoblast membranes, and intravenous immunoglobulin provide no significant beneficial effect over placebo in improving the live birth rate.

Bouquet variety of antiphospholipid antibodies in recurrent pregnancy loss

Seventy-six female patients with two or more recurrent pregnancy losses (RPL) during the 1(st) trimester were studied. Based on the results of the aCL and aB2GPI antibodies testing, patients were divided in two groups: 22 patients with RPL and elevated immunoglobulin (Ig) G/IgM aCL and/or aB2GPI [RPL + antiphospholipid syndrome (APS)] and 54 patients with RPL alone (without high antibodies). Immunoglobulin G aPS and IgG a-AnV in patients with RPL + APS were higher than in controls and IgG aPS were higher in RPL + APS than in RPL alone. Additionally IgG a-AnV and IgM aPE are higher in RPL alone than in controls. In 18/22 (81%) patients with RPL + APS and 29/54 (54%) patients with RPL alone, there were one or more positive antibodies: aPS, aPT, a-AnV or aPE. These results raise a question whether or not these antiphospholipid antibodies should be routinely tested in women with RPL and especially in the context of the so-called "seronegative APS".

Increase of peripheral blood TCD8+ cells in women with recurrent miscarriage

Recurrent miscarriage (RM) is one of the most prevalent reproductive problems faced by couples that may affect as many as 2% of women in reproductive age. The causes of its abnormality have attracted the attention of many researchers. We aim to determine the different T-cell subsets in women with RM and normal control. In this prospective case-control study, peripheral blood was taken from women with RM (n = 25) and normal women (n = 17), during the mid-luteal phase. The percentage of CD3, CD3(+)CD4(+), CD3(+)CD8(+) markers and also CD4/CD8 ratio was detected in the patients and control group by flow cytometry. The proportion of TCD8(+) was significantly higher in RM women compared with the control group (p < 0.05). However, there was no statistical difference in percentage of total TCD3(+) and TCD4(+) cells between the RM and control women. Also, the CD4/CD8 ratio was lower in the RM women compared with the control women. These observations support the concept that increase of TCD8(+) lymphocytes could be involved in the aetiology of RM.

Elevated procoagulant endothelial and tissue factor expressing microparticles in women with recurrent pregnancy loss

BACKGROUND

15% of reproducing couples suffer from pregnancy loss(PL) and recurs in 2-3%. One of the most frequently hypothesized causes of unexplained PL refers to a defective maternal haemostatic response leading to uteroplacental thrombosis. Hereditary thrombophilia and antiphospholipid antibodies have been extensively described as risk factors for PL in women with unknown aetiology. Recently, a new marker has emerged: the cell-derived procoagulant circulating microparticles(MPs) which have been reported to have a major role in many thrombosis complicated diseases. This study aims to analyze the significance of procoagulant MPs in women suffering from unexplained recurrent pregnancy loss(RPL), and characterize their cellular origin.

METHOD AND FINDINGS

115 women with RPL were analyzed for common thrombophilia markers and different cell derived MPs-total annexinV, platelet(CD41a), endothelial(CD146,CD62e), leukocyte(CD45), erythrocyte(CD235a) and tissue factor(CD142)(TF) expressing MPs and were compared with 20 healthy non-pregnant women. Methodology for MP analysis was standardized by participating in the "Vascular Biology Scientific and Standardization Committee workshop".

RESULTS

Total annexinV, TF and endothelial MPs were found significantly increased(p<0.05, 95% confidence interval) in women with RPL. The procoagulant activity of MPs measured by STA-PPL clotting time assay was found in correspondence with annexinV MP levels, wherein the clot time was shortened in samples with increased MP levels. Differences in platelet, leukocyte and erythrocyte derived MPs were not significant. Thirty seven of 115 women were found to carry any of the acquired or hereditary thrombophilia markers. No significant differences were seen in the MP profile of women with and without thrombophilia marker.

CONCLUSION

The presence of elevated endothelial, TF and phosphatidylserine expressing MPs at a distance (at least 3 months) from the PL suggests a continued chronic endothelial damage/activation which may get exaggerated at the onset of pregnancy. The data suggests that MPs may contribute to uteroplacental thrombosis and are associated with the pathogenesis of RPL.

Progestogen for preventing miscarriage

BACKGROUND

Progesterone, a female sex hormone, is known to induce secretory changes in the lining of the uterus essential for successful implantation of a fertilized egg. It has been suggested that a causative factor in many cases of miscarriage may be inadequate secretion of progesterone. Therefore, progestogens have been used, beginning in the first trimester of pregnancy, in an attempt to prevent spontaneous miscarriage.

OBJECTIVES

To determine the efficacy and safety of progestogens as a preventative therapy against miscarriage.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 August 2013), reference lists from relevant articles, attempting to contact authors where necessary, and contacted experts in the field for unpublished works.

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials comparing progestogens with placebo or no treatment given in an effort to prevent miscarriage.

DATA COLLECTION AND ANALYSIS

Two review authors assessed trial quality and extracted data.

MAIN RESULTS

Fourteen trials (2158 women) are included. The meta-analysis of all women, regardless of gravidity and number of previous miscarriages, showed no statistically significant difference in the risk of miscarriage between progestogen and placebo or no treatment groups (Peto odds ratio (Peto OR) 0.99; 95% confidence interval (CI) 0.78 to 1.24) and no statistically significant difference in the incidence of adverse effect in either mother or baby.A subgroup analysis of placebo controlled trials did not find a difference in the rate of miscarriage with the use of progestogen (10 trials, 1028 women; Peto OR 1.15; 95% CI 0.88 to 1.50).In a subgroup analysis of four trials involving women who had recurrent miscarriages (three or more consecutive miscarriages; four trials, 225 women), progestogen treatment showed a statistically significant decrease in miscarriage rate compared to placebo or no treatment (Peto OR 0.39; 95% CI 0.21 to 0.72). However, these four trials were of poorer methodological quality. No statistically significant differences were found between the route of administration of progestogen (oral, intramuscular, vaginal) versus placebo or no treatment. No significant differences in the rates of preterm birth, neonatal death, or fetal genital anomalies/virilization were found between progestogen therapy versus placebo/control.

AUTHORS' CONCLUSIONS

There is no evidence to support the routine use of progestogen to prevent miscarriage in early to mid-pregnancy. However, there seems to be evidence of benefit in women with a history of recurrent miscarriage. Treatment for these women may be warranted given the reduced rates of miscarriage in the treatment group and the finding of no statistically significant difference between treatment and control groups in rates of adverse effects suffered by either mother or baby in the available evidence. Larger trials are currently underway to inform treatment for this group of women.

Thromboembolism risk following recurrent miscarriage

Normal pregnancy is associated with extensive changes in hemostasis such that the procoagulant effect becomes dominant. The evolutionary advantage of this hypercoagulability may be to counteract the inherent instability associated with hemochorial placentation, which is unique to human beings. However, overall, there is a four- to 10-fold increased thrombotic risk throughout gestation and the postpartum period. Certain inherited or acquired thrombophilic factors may predispose to arterial and/or venous thrombosis and have a possible association with pregnancy complications, including recurrent miscarriage (RM), which affects up to 5% of couples with childbearing desire. A subgroup of women with RM has been demonstrated to be in a prothombotic state before and after pregnancy. The long-term health implications of this hypercoagulability may imply an increased risk of ischemic heart disease. Moreover, the presence of antiphospholipid antibodies rather than thrombophilic genetic defects (i.e., factor V Leiden or prothrombin G202010A mutation) in patients with RM is a determinant of thrombotic events later in life, especially among those patients having also cardiovascular risk factors. This article highlights the thromboembolic risk in nonpregnant RM patients in different thrombophilic settings and the need for thromboprophylaxis among these patients.

HLA-G Expression Pattern: Reliable Assessment for Pregnancy Outcome Prediction

Because mothers and fathers are more or less dissimilar at multiple HLA loci, mother considers her fetus as a semi-allograft. Mother's immune system may recognize paternal HLA as foreign antigen and may develop anti-paternal HLA antibodies and cytotoxic T lymphocyte. There are some mechanisms that modulate maternal immune responses during pregnancy, in order to make uterus an immune privileged site. This immunosuppression is believed to be mediated, at least partly, by HLA-G, non-classical class I human leukocyte antigen (HLA) molecule that is strongly expressed in cytotrophoblast and placenta. The major HLA-G function is its ability to inhibit T and B lymphocytes, NK cells and antigen-presenting cells (APC).Since HLA-G is expressed strongly at the maternofetal interface and has an essential role in immunosuppression, HLA-G polymorphism and altered expression of HLA-G seems to be associated with some complications of pregnancy, such as pre-eclampsia, recurrent misscariage and failure in IVF.This perspective discusses recent findings about HLA-G genetics, function, expression and polymorphism; and focus on HLA-G role in the etiology of recurrent miscarriage.

Blockage of heme oxygenase-1 abrogates the protective effect of regulatory T cells on murine pregnancy and promotes the maturation of dendritic cells

Regulatory T cells (Treg) play an important role in fetal protection. They expand during normal pregnancy and protect fetal antigens from maternal effector cells. Their effect is associated with the up-regulation of tolerance-associated molecules at the fetal-maternal interface. Among these, Heme Oxygenase-1 (HO-1, coded by Hmox1) is of special importance as its blockage correlates with increased abortion rates and its up-regulation positively affects pregnancy outcome. Here, we aimed to investigate whether the protective effect of Treg is mediated by HO-1 in a mouse model. HO-1 blockage by Zinc Protoporhyrin (ZnPPIX) abrogated the protective effect of Treg transfer. We found that HO-1 is important in maintaining maternal dendritic cells (DCs) in an immature state, which contributes to the expansion of the peripheral Treg population. This brings to light one essential pathway through which Treg mediates the semi-allogeneic fetus tolerance.

The involvement of inflammatory cytokines in the pathogenesis of recurrent miscarriage

OBJECTIVE

To investigate the inflammatory cytokine expression pattern in trophoblastic tissue from women with unexplained recurrent miscarriage (RM).

STUDY DESIGN

Trophoblasts were obtained during uterine evacuation from 11 women with RM and from 20 healthy pregnant women undergoing elective termination of pregnancy, who served as controls. The array was performed using GEArray Q Series Human Inflammatory Cytokines & Receptors Gene Array HS-015 membranes. Data were confirmed by quantitative real-time PCR. The Mann-Whitney U test was performed for statistical analysis.

RESULTS

Microarray analysis identified three genes that were differentially expressed between RM patients and controls. We observed significant downregulation of Transforming Growth Factor beta 3 (TGF-β3) and Interleukin 25 (IL-25) (5-fold reduction and 2.5-fold reduction, respectively) and significant upregulation of CD-25, also known as Interleukin 2 receptor alpha (IL-2RA) (7-fold increase) in women with RM compared with controls. The median ΔC(t) of TGF-β3 was 8.2 (interquartile range, 7.67-8.9) in RM patients vs. 5.85 (interquartile range, 5.3-6.09) in controls; the median ΔC(t) of IL-25 was 5.18 (interquartile range, 4.46-5.76) in RM patients vs. 3.85 (interquartile range, 3.6-4.51) in controls, and the median ΔC(t) of CD-25 was 9.62 (interquartile range, 7.81-12.42) in RM patients vs. 12.44 (interquartile range, 11.02-13.86) in controls.

DISCUSSION

Our results suggest that the immunological and inflammatory regulation mechanisms of the placental environment play a key role in recurrent miscarriage. The observed trophoblast cytokine expression pattern at the maternal-fetal interface confirms the immunotrophic theory, as demonstrated by a switch from a T-helper-1 (Th1) profile to a T-helper-2 (Th2) profile in women who experience recurrent miscarriages.

Recurrent early pregnancy loss and consanguinity in Omani couples

Consanguinity is common in Arab countries. The Sultanate of Oman has a relatively small population with a high prevalence of consanguineous marriages. This is a retrospective study of women who had three or more consecutive miscarriages between January 2002 and December 2008, investigated in the non-pregnant state. Age, parity, menstrual history, number of miscarriages, personal and family history, history of consanguinity and investigations were collected for 141 patients. The mean number of miscarriages was 3.4; 53% of the women had a consanguineous marriage, 42% were non-consanguineous and in 5% the marital interrelationship was unknown. There was no significant difference in the prevalence of parental karyotype abnormalities, anticardiolipin antibodies, antinuclear antibodies, thyroid disorders, or lupus between the consanguineous and non-consanguineous couples. Consanguinity appeared not to play a significant role in the etiology of recurrent spontaneous miscarriage.