Development Of Recurrent Pregnancy Loss Research Articles

Роль вітаміну D в генезі звичних репродуктивних втрат

Currently, there is active discussion worldwide regarding the impact of vitamin D deficiency and the manifestations of its immunosuppressive properties on the development of recurrent pregnancy loss. Vitamin D deficiency and insufficiency are quite common, with prevalence ranging from 35% to 80%. Despite modern molecular-genetic technologies, the question of polymorphisms in the vitamin D receptor (VDR) genes remains relevant. Purpose - analysis of the relationship between VDR genes polymorphisms in women affected by recurrent reproductive loss. A systematic search of published literature with a meta-analysis was conducted using the PubMed, Web of Science, and Scopus databases for the period from 2021 to 2022. This review examines the association VDR in women with recurrent reproductive losses. There is a connection between low vitamin D levels and the risk of developing various somatic diseases. The review of scientific data confirmed information about the comorbidity of diseases related to vitamin D deficiency or insufficiency. Thus, extragenital pathology creates unfavorable conditions for recurrent pregnancy losses, limits adaptive mechanisms, and contributes to the exacerbation of complications that may arise due to vitamin D deficiency or insufficiency. During the review, it was found that the most prevalent and well-studied polymorphic variants of the VDR gene, such as FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), TaqI (rs731236), and Cdx2, are associated with various diseases, including reproductive losses. In particular, the FokI polymorphism (rs2228570) of the VDR gene acts as an independent factor capable of predicting the level of vitamin D in the blood, influencing pregnancy outcomes. Conclusions. The obtained data represent significant information for assessing the risk of recurrent reproductive losses and developing new strategies for the prevention and treatment of these conditions. No conflict of interests was declared by the authors.

The role of polymorphisms in the genes of the hemostasis system and the folate-methionine cycle in the development of recurrent pregnancy loss

BACKGROUND:Recurrent pregnancy loss is a serious clinical problem that complicates about 2% of pregnancies. There is evidence that thrombophilia and disorders of folate-methionine metabolism may cause recurrent pregnancy loss.
 AIM:The aim of this study was to evaluate the contribution of polymorphic variants of the genes of the hemostasis system and the folate-methionine cycle in women with recurrent pregnancy loss.
 MATERIALS AND METHODS:Clinical examination of 406 pregnant women divided into two study groups was carried out. The main study group consisted of 206 women with two or more pregnancy losses known up to 12 weeks of pregnancy; the control group included 200 apparently healthy women with a known history of two or more live births, no spontaneous or induced abortions, infertility, or endometriosis. All patients underwent a molecular genetic study of 12 single nucleotide polymorphisms in the genes of the hemostasis system and the folate-methionine cycle performed by real-time polymerase chain reaction.
 RESULTS:We studied single nucleotide polymorphisms in eight genes involved in the hemostasis system and in four genes of the folate-methionine cycle. An association of presence of alternative variants such as 1565C (rs5918) of theITGB3integrin beta-3 gene and A66G (rs1801394) of theMTRRmethionine synthase reductase gene with the development of recurrent pregnancy loss was found. The frequency of their occurrence was 29.1 and 77.7% in the recurrent pregnancy loss group vs. 12.0 and 49.0% in the control group, respectively (p 0.01). The combined carriage of the alternative variants 1565C (rs5918) of theITGB3gene and A66G (rs1801394) of theMTRRgene in the recurrent pregnancy loss group was diagnosed more often than in the control group and amounted to 47 (22.8%) vs. 12 (6.0%) cases ( = 5.047;p 0.01; odds ratio 3.631; 95% confidence interval 2.3749.034). We have thus developed a three-locus model of the synergetic action of allelic variants of the above genes in the development of recurrent pregnancy loss in early pregnancy [10976 GA (rs6046) of theF7, 455 GA (rs1800790) of theFGB, 1565 TC (rs5918) of theITGB3] with reproducibility of 8/10, sensitivity of 65.6%, and specificity of 68.8% ( = 15.7415,p 0.0001; odds ratio 3.341, 95% confidence interval 1.8246.118).
 CONCLUSIONS:This study allows for confirming the hypothesis that the status of genetic variants of theITGB3andMTRRgenes and the association of three single nucleotide polymorphisms: rs6046 of theF7, rs1800790 of theFGB, and rs5918 of theITGB3may be used as predictors of recurrent pregnancy loss development.

Determining the risk of miscarriage in genetic forms of thrombophilia

The aim: to study the distribution and influence of coagulation factor gene polymorphisms and endothelial dysfunction on the development of recurrent pregnancy loss.
 Materials and methods: a prospective case-control study included 109 pregnant women in the 1st trimester with habitual miscarriage and 34 conditionally healthy pregnant women with an uncomplicated obstetrical anamnesis without risk factors for miscarriage. Genetic polymorphisms of coagulation and fibrinolysis factors (1691 G→A FVL, 20210 G→A prothrombin, 675 5G/4G PAI-1, 455 G→A fibrinogen β), as well as endothelial dysfunctions (192 Q→R PON-1, 677 C → T MTHFR) were investigated using allele-specific polymerase chain reaction.
 Results: Pathological polymorphisms of the genes of the hemostasis system and endothelial dysfunction play a significant role in the development of miscarriage, namely such pathological genotypes as 1691 GA of factor V Leiden - increases the risk by 5.3 times (95 % CI 1.5-18.5), 20210 GA of prothrombin - by 26.47 times (1.6-445.7), 675 4G/4G PAI-1 - by 7, 5 times (1.7-33.79), -455AA fibrinogen β - 9.7 times (1.3-74.16), 677 CT MTHFR - 2.6 times (1.0-6.2), 677 TT MTHFR - 21.7 times (1.3-368.6). Multigenic forms of thrombophilia predominate in the majority of patients with miscarriage and account for 76.1 % (p<0.001, OR=12.31, 95 % CI 4.8-31.55). It was determined that the simultaneous presence of two pathological polymorphisms increases the risk of miscarriage by 3.88 times (OR 3.38; 95 % CI 1.26-9.97), and three ones - more than 2.5 times (OR 2.66; 95 % CI 1.02-7.19).
 Conclusions: the course of pregnancy against the background of pathological polymorphisms of the genes of the hemostasis system and endothelial dysfunction significantly increases the risk of habitual miscarriage, which should be considered when planning a pregnancy in women with habitual miscarriage

MiR604A>G gene polymorphism is associated with recurrent pregnancy loss in Turkish women.

Recurrent pregnancy loss is considerably a reproductive health problem for couples. Genetic, epigenetic, and environmental factors play an important role in the development of recurrent pregnancy loss. While there are many causes, genetic and epigenetic factors are common. Inthis study, we aimed to examine the association between miR604 (rs2368393) A>G gene polymorphism and the risk of recurrent miscarriage in the Turkish population. The study included 250 participants (i.e., 150 patients and 100 controls). DNA samples were isolated from peripheral blood, and polymerase chain reactions and restriction fragment length polymorphism methodologies were applied. The genotype distribution and allele frequencies of miR604A>G gene showed statistically significant differences between patients and control groups (p=0.002 and p<0.002, respectively). As a result of the study, we found that the AA genotype and A allele of the miR604A>G gene were statistically significant for the risk of recurrent pregnancy loss in Turkish women.

Maternal Thrombophilic and Hypofibrinolytic Genetic Variants in Idiopathic Recurrent Pregnancy Loss: a Continuing Mystery.

Despite the fact that multiple recurrent pregnancy loss (RPL) etiologies have been identified, 50-70% of RPL cases remain enigmatic, and idiopathic RPL is still a serious medical challenge. A plethora of studies have investigated the correlation of RPL with variations in coagulation and/or fibrinolytic factors-encoding genes. Notwithstanding, evidence for a link between these variations and RPL remains discordant. We aimed to explore the association of thrombophilic and hypofibrinolytic gene variations with RPL development. Two hundred Saudi women were recruited in this study, comprising 150 women experiencing RPL and 50 healthy women. Thirteen genetic variants, including FV G1691A, FV A4070G, F2 G20210A, F13A1 G103T, FGB - 455G > A, PAI-1 - 675 4G/5G, ITGB3 T1565C, MTHFR C677T, MTHFR A1298C, ACE I/D, APOB G10708A, APOE T388C, and APOE C526T were genotyped using ViennaLab StripAssay. Women experiencing RPL harbor significantly higher frequencies of the F13A1 103T, FGB - 455A, and ITGB3 1565C alleles than control women (p < 0.001). No differences in the prevalence of other investigated variants were identified between control women and those with RPL. No considerable link of F5 1691G > A/4070A > G, MTHFR 677C > T/1298A > C, and APOE 388T > C/526C > T haplotypes with RPL risk was demonstrated. F13A1 G103T, FGB - 455G > A, and ITGB3 T1565C variants are connected to a higher likelihood of developing RPL and, hence, may have the potential to identify those women at risk of RPL, thereby, improving RPL susceptibility prediction. Incorporating molecular testing of thrombophilic and hypofibrinolytic genetic variants into routine workup could confer a promising approach for refined RPL risk assessment.

Anxiety and depression are risk factors for recurrent pregnancy loss: a nested case\u2013control study

BackgroundTo evaluate the interaction of depression and anxiety with the development of recurrent pregnancy loss (RPL).MethodsA nested case–control study involving 2558 participants was conducted with data from the prospective Miscarriage Woman Cohort study between 2017 and 2019 in the province of Gansu, China. The questionnaire data, self-rating anxiety scale and self-rating depression scale were collected after each participant’s first miscarriage. Information on RPL outcomes was obtained from the medical records within the subsequent 2 years. All patients diagosed RPL were recruited as cases whilst a randomly selected group of women with only one miscarriage in the past were recruited as controls. The logistic regression and the interaction effects between anxiety and depression and RPL were analysed.ResultsThe prevalence of anxiety (n = 325, 28.7% vs. n = 278, 19.5%) and depression symptoms (n = 550, 48.6% vs. n = 589, 41.3%) for the 1132 RPL cases were higher than 1426 non-RPL controls (P < 0.001). After adjusting for possible confounding variables, the odds ratio (OR) value, reflecting the multiplicative interaction, was 1.91 (95% CI 1.50–2.44, P < 0.001) for cases with both anxiety and depression symptoms compared with the non-RPL group. The relative excess risk of interaction value, reflecting the additive interaction between anxiety and depression to RPL was 1.15 (95% CI 0.32–4.21). Moreover, the adjusted OR for RPL cases with mild anxiety and severe depression was 2.77 (95% CI 1.07–44.14, P < 0.001), for RPL cases with severe anxiety and mild depression was 4.23 (95% CI 1.01–22.21, P < 0.001), for RPL cases with severe anxiety and moderate depression was 4.34 (95% CI 1.03–21.28, P < 0.001) and for RPL cases with severe anxiety and severe depression was 5.95 (95% CI 1.09–45.09, P < 0.05).ConclusionsEither depression or anxiety alone could increase the risk of subsequent RPL. Anxiety and depression had a synergistic effect after the first miscarriage which increased the development of subsequent RPL disease.

Circular RNA FOXP1 relieves trophoblastic cell dysfunction in recurrent pregnancy loss via the miR-143-3p/S100A11 cascade

ABSTRACT Recurrent pregnancy loss (RPL) is closely associated with insufficient functions of trophoblastic cells. Circular RNA forkhead box P1 (circFOXP1) can regulate cell activities in different types of diseases. However, its effects on trophoblastic cells and its role in RPL development remain unknown. In this study, gene expressions were detected by RT-qPCR. Protein levels were detected by Western blotting. Trophoblastic cell viability, apoptosis, invasion, and migration were respectively analyzed via CCK-8, flow cytometry, wound healing, and transwell assays. The association between miR–143–3p and circFOXP1 or S100A11 (S100 calcium binding protein A11) was explored and confirmed by bioinformatics prediction and luciferase reporter assay. Herein, miR–143–3p was upregulated in RPL. Furthermore, miR–143–3p upregulation induced apoptosis and suppressed proliferation, epithelial-to-mesenchymal transition (EMT) process, and metastatic capabilities of trophoblastic cells; whereas, miR–143–3p inhibition exert opposite effects. MiR–143–3p targeted S100A11 and was adversely regulated by circFOXP1 expression. S100A11 inhibition partially offset the effect of miR–143–3p knockdown on trophoblastic cell viability, apoptosis, EMT, invasion, and migration. In addition, circFOXP1 competitively combined with miR–143–3p, thus regulating S100A11 expression. Moreover, circFOXP1 regulated trophoblastic cell functions through the miR–143–3p/S100A11 cascade. To sum up, our study, for the first time, demonstrated that circFOXP1 could improve dysfunction of trophoblastic cells through the miR–143–3p/S100A11 axis, providing novel biomarkers and diagnostic targets for RPL.

Runs of homozygosity in spontaneous abortions from families with recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a severe reproductive pathology with a significant component of unexplained etiology. Extended homozygous regions as a possible etiological factor for RPL were sought in the genomes of embryos. Twenty-two paired first-trimester spontaneously aborted embryos from eleven women with recurrent miscarriage were analyzed. All embryos had normal karyotypes according to metaphase karyotyping and conventional comparative genomic hybridization. SurePrint G3 Human CGH + SNP 4 × 180K microarrays (Agilent Technologies) were used to search for homozygous regions. As a result, 39 runs of homozygosity (ROH) were identified in extraembryonic tissues of 15 abortuses. Verification of recurrent homozygous regions was performed by Sanger sequencing. The presence of occasional heterozygous SNPs was shown in 25 extended ROHs, which may indicate that they did not arise de novo but were inherited from parents. In the course of inheritance in a series of generations, they may accumulate mutations, leading to heterozygosity for several sites in the initially homozygous population-specific regions. Homozygotization of recessive mutations is one of the putative mechanisms of the influence of such inherited ROHs on RPL development. The high frequency of extended ROHs detected in the present study may point to a role of inbreeding in RPL etiology. Homozygous regions may also occur due to uniparental disomy, and abnormalities of genomic imprinting may be another mechanism responsible for the pathological manifestation of ROHs in embryogenesis. Indeed, five predicted imprinted genes were identified within ROHs according to the Geneimprint database: OBSCN, HIST3H2BB, LMX1B, CELF4, and FAM59A. This work reports the first finding of a high frequency of extended ROHs in spontaneously aborted embryos with normal karyotypes from families with RPL.

Association of genetic polymorphisms in VEGF -460, -7 and -583 and hematocrit level with the development of idiopathic recurrent pregnancy loss and a meta-analysis.

The present study was performed to investigate whether genetic variants of VEGF are associated with recurrent pregnancy loss (RPL) in Korean women and to provide insight into the role of VEGF in the pathogenesis of RPL development. A cohort of 384 women with idiopathic RPL with a history of two or more uxexplained consecutive early pregnancy losses and 236 control women were recruited from an infertility center of university-teaching hospital in Korea between March 1999 and February 2010. We examined three VEGF polymorphisms (rs833061, rs3025020 and rs25648). Genotyping was assessed by polymerase chain reaction (PCR)-restriction fragment length polymorphism analyses (rs3025020) or real-time PCR (rs833061, rs25648). There was no statistically significant difference in frequency of each three VEGF polymorphic loci between the control and RPL groups. Allele combinations of VEGF rs3025020/rs833061 TT/TC and TT/TC+CC genotypes were associated with an increased frequency of RPL development [odds ratio (OR)=3.525, 95% confidence interval (CI)=1.154-10.767, p=0.027 and OR=3.815, 95% CI=1.256-11.588, p=0.018, respectively]. Haplotype analysis revealed that two allele combinations (rs833061/rs3025020 C-T and rs25648/rs3025020 T-T) were associated with an increased prevalence of RPL (OR=2.548, 95% CI=1.502-4.320, p=0.0004 and OR=16.50, 95% CI=0.976-278.8, p=0.003, respectively). Allele combinations and haplotypes of rs3025020/rs833061 were associated with maternal blood hematocrit (HCT) levels in the RPL group (p=0.048 and 0.006, respectively). The VEGF rs833061/rs3025020 genotype allele was related to the development of RPL and was also associated with maternal blood HCT levels in RPL patients. However, further studies are needed to clarify the exact mechanism of how VEGF and HCT are involved in RPL development.

MiR-27a and miR-449b polymorphisms associated with a risk of idiopathic recurrent pregnancy loss.

ObjectiveMicroRNAs (miRNAs) regulate gene expression during the peri-implantation period. The purpose of this study was to investigate whether genetic polymorphisms in the four miRNAs associated with fetal or placental development play roles in the development of idiopathic recurrent pregnancy loss (RPL) in Korean females.Study designA case-control study involving 225 controls and 387 women with at least two consecutively recurrent pregnancy losses between 1999 and 2012 was performed. The genotypes of the four miRNA polymorphisms, including miR-27a rs895819, miR-423 rs6505162, miR-449b rs10061133, and miR-605 rs2043556, were analyzed by the polymerase chain reaction-restriction fragment length polymorphism assay. Odds ratios and 95% confidence intervals were estimated using multivariate analyses after maternal age adjustments. The relationships between each of the four microRNA genotypes and each of the six clinical parameters of the RPL patients (plasma homocysteine and folate levels, natural killer cell number, platelet count, prothrombin time, and, activated partial thromboplastin time) were analyzed using multiple linear regression analyses.ResultsOur results suggest that weak associations between decreased RPL risk and the genotypes of miR-27a (AG and AG+GG), combination genotype of miR-27a/miR-423 (AG/GC), and haplotypes of miR-27a/miR-423/miR-449b/miR-605 (G-C-A-G) and miR-27a/miR-449b/miR-605 (G-A-G), whereas weak associations between increased RPL risk and genotypes of miR-449b (GG and AG+GG), combination genotypes of miR-423/miR-449b (CC/GG and CA/AG), miR-449b/miR-605 (AG/AG), haplotypes of miR-27a/miR-423/miR-449b/miR-605 (A-C-G-A, A-A-A-G, and G-C-G-G), miR-27a/miR-423/miR-449b (A-C-G), miR-27a/miR-449b/miR-605 (A-A-G, A-G-A, and G-G-G), miR-423/miR-449b/miR-605 (C-G-G and A-A-G), and miR-423/miR-449b (C-G and A-A). The genotypes of miR-27a (AG and AG+GG) also showed significant contributions to the prediction of folate levels in RPL patients.ConclusionsThe study showed associations between miRNA polymorphisms (miR-27a rs895819 and miR-449b rs10061133) and RPL development, and between the miRNA polymorphism (miR-27a rs895819) and plasma folate levels.

Estrogen receptor beta gene polymorphisms and risk of recurrent pregnancy loss: a case–control study

Estrogen might play a key role in the maintenance of pregnancy. We investigated the role of the ER-β gene +1730 G/A, +1082 G/A, and CA repeat polymorphisms in Korean patients with recurrent pregnancy loss (RPL). Genotyping was performed using the TaqMan assay in 305 patients with at least two unexplained consecutive spontaneous miscarriages before 20 weeks of gestation and 299 controls. The genotype distributions of the ER-β gene +1082 G/A and +1730 G/A polymorphisms in the RPL group did not differ from those in the control group. When the analysis was restricted to patients with three or more consecutive spontaneous miscarriages, there were also no differences in the genotype distribution between this subgroup and controls. The number of CA repeats was distributed from 13 to 28 with two large peaks at 18 and 23 in patients with RPL and controls. Using the two major peaks as cut-offs, the allele distributions were compared between patients and controls. However, the distribution of ER-β gene CA repeats did not differ between women with recurrent miscarriage and controls. Findings of the current study suggest that the ER-β gene polymorphisms are not major determinants of the development of RPL in Korean women.

High mobility group box 1 protein polymorphism affects susceptibility to recurrent pregnancy loss by up-regulating gene expression in chorionic villi.

Inflammation in chorionic villi is involved in the development of recurrent pregnancy loss (RPL). High mobility group box 1 protein (HMGB1) plays critical roles in inflammation and expression of the protein can be found in chorionic villi. The purpose of the study was to investigate the association between HMGB1 genetic polymorphisms and susceptibility to RPL and to examine the mechanism underlying this correlation. Two HMGB1 polymorphisms, rs2249825C/G and rs1412125T/C, were examined in 112 RPL patients and 118 healthy controls by the polymerase chain reaction-restriction fragment length polymorphism assay. Percentage of rs2249825GG was significantly increased in patients than in controls (Odd ratio [OR] =2.33, 95 % confidence interval [CI]: 1.18-4.58, P = 0.013). Also, prevalence of rs2249825G allele was significantly higher in RPL cases (OR = 1.77, 95 % CI: 1.20-2.62, P = 0.004). Function analysis of rs2249825C/G revealed that the polymorphism did not affect serum level of HMGB1. Interestingly, we found significantly increased level of HMGB1 in chorionic villi from RPL patients. Moreover, patients with rs2249825GG genotype presented significantly elevated level of HMGB1 in chorionic villi compared to those with CG or CC genotypes. These results suggest that HMGB1 rs2249825C/G polymorphism is associated with increased risk of RPL and can elevate gene expression in chorionic villi.

Meta-analysis of the association between plasminogen activator inhibitor-1 4G/5G polymorphism and recurrent pregnancy loss.

BackgroundThe association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and recurrent pregnancy loss (RPL) risk is still contradictory. We thus performed a meta-analysis.Material/MethodsRelevant studies were searched for in PubMed, Web of Science, Embase, and Cochrane Library. An odds ratio (OR) with a 95% confidence interval (CI) was used to assess the association between PAI-1 4G/5G polymorphism and RPL risk.ResultsA total of 22 studies with 4306 cases and 3076 controls were included in this meta-analysis. We found that PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk (OR=1.89; 95% CI 1.34–2.67; P=0.0003). In the subgroup analysis by race, PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk in Caucasians (OR=2.23; 95% CI 1.44–3.46; P=0.0003). However, no significant association was observed in Asians (OR=1.47; 95% CI 0.84–2.59; P=0.18).ConclusionsIn conclusion, this meta-analysis suggests that PAI-1 4G/5G polymorphism might be associated with RPL development in Caucasians.

The PAI-1 4G/5G and ACE I/D polymorphisms and risk of recurrent pregnancy loss: a case-control study.

Thrombophilia has been postulated to be a contributor to the pathophysiology of recurrent pregnancy loss (RPL). We investigated the role of the plasminogen activator inhibitor type 1 (PAI-1) 4G/5G and angiotensin converting enzyme (ACE) I/D polymorphisms in Korean patients with RPL. Genotyping was performed using the TaqMan assay in 227 RPL patients and 304 controls. The genotype distributions of both polymorphisms in the RPL group did not differ from those of controls. Because the frequency of being homozygous for ACE D/D and the PAI-I 4G/4G combination has been reported to be significantly higher in RPL patients, this was also analyzed. However, no significant difference was noted; 3.1% of RPL patients had both ACE D/D and PAI-I 4G/4G, as did 4.9% of controls (P=0.791). The current study suggests that both polymorphisms, either alone or in combination, are not major determinants of the development of RPL in Korean women.

Genetic Variants in MicroRNA Machinery Genes Are Associate with Idiopathic Recurrent Pregnancy Loss Risk

ObjectiveKey molecules involved in microRNA (miRNA) biogenesis, such as DROSHA, XPO5, and DICER, have been identified in trophoblast cells, confirming that the miRNA biogenesis pathway is active in human placenta. In addition, miRNAs regulate uterine gene expression associated with inflammatory responses during the peri-implantation period and participate in maternal-fetal immune tolerance. The purpose of this study was to demonstrate whether genetic polymorphisms in miRNA machinery genes show an association with idiopathic recurrent pregnancy loss (RPL) in Korean women.Study designWe performed a case-control study with 238 controls and 338 women who had experienced at least two consecutive pregnancy losses between 1999 and 2010. Genotypes of miRNA machinery genes, including DICER rs3742330, DROSHA rs10719, RAN GTPase (RAN) rs14035, and exportin-5 (XPO5) rs11077 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The logistic odds ratios (ORs) of RPL were estimated with a 95% confidence interval (CI) in multivariate analysis after maternal age adjustment. Gene-gene interactions among the loci of the four gene polymorphisms were evaluated using the multifactor dimensionality reduction (MDR) method.ResultsThe RAN rs14035 CC genotype and DICER rs3742330/DROSHA rs10719 GG/TC+CC, rs3742330/RAN rs14035 GG/CC, and DICER rs3742330/XPO5 rs11077 GG/AC+CC combinations were significantly associated with increased RPL risk, whereas the RAN rs14035 CT, DICER rs3742330/RAN rs14035 AA+AG/CT+TT, DROSHA rs10719/RAN rs14035 TC+CC/CT+TT, and RAN rs14035/XPO5 rs11077 CT+TT/AA combinations reduced RPL risk. The A-T-T-C and G-C-T-A allele combinations (DICER/DROSHA/RAN/XPO5) were 20 times more frequent in the RPL group than in the control group.ConclusionOur study demonstrates the relationship between RPL development and the polymorphism of the miRNA machinery gene RAN and combined genotype of DROSHA/DICER.

Genetic association studies of endothelial nitric oxide synthase gene polymorphisms in women with unexplained recurrent pregnancy loss: a systematic and meta-analysis

Recurrent pregnancy loss (RPL) is a multifactorial disorder, both genetic and environmental factors contribute to the development of RPL. Recently, the association between endothelial nitric oxide synthase (eNOS) gene polymorphisms and unexplained recurrent pregnancy loss (URPL) has been reported, and the results were inconsistent. Hence, we performed the meta-analysis to drive a more precise estimation of association between eNOS polymorphisms and URPL. Odds ratio (OR) and its 95% confidence interval were calculated under co-dominant (AA vs. BB, TT vs. GG) and additive (A vs. B, T vs. G) genetic models. Studies of eNOS intron 4 VNTR and Glu298Asp were separated by ethnicities. 13 studies included 1,769 URPL cases and 1,376 healthy controls on eNOS intron 4 VNTR polymorphism, and 11 studies were involved in Glu298Asp polymorphism with 1,498 URPL cases and 1,123 healthy controls. The integrated results showed that eNOS Glu298Asp polymorphism was associated with URPL [ORs were 1.91 (1.42-2.56), P < 0.001; 1.67 (1.36-2.04), P < 0.001, respectively]. When analyses were separated by ethnic subgroups, the association between eNOS Glu298Asp polymorphism and URPL was only observed in East Asians [OR = 1.88 (1.52-2.33), P < 0.001 under additive model], and there was no association between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians. The results indicated a significant association between eNOS Glu298Asp polymorphism and URPL in East Asians. No association was observed between eNOS intron 4 VNTR polymorphism and URPL in Caucasians and East Asians.

Association of methionine synthase and thymidylate synthase genetic polymorphisms with idiopathic recurrent pregnancy loss

To investigate the association between one-carbon metabolism and recurrent pregnancy loss (RPL). One-carbon metabolism is important for maintaining pregnancy, and the enzymes codified by these genes are relevant to this metabolic pathway. Case-control study. An urban university-based hospital in South Korea. A cohort of 353 RPL patients (3.09 ± 1.65 pregnancy losses) and 226 control subjects. None. Genotyping was assessed by polymerase chain reaction-restriction fragment length polymorphism assay. We examined polymorphisms in four genes: methionine synthase (MTR); methionine synthase reductase (MTRR); methylenetetrahydrofolate dehydrogenase 1 (MTHFD1); and thymidylate synthase (TS). The MTR 2756AA polymorphism was associated with RPL. Gene-gene interaction analysis revealed that the frequency of the MTR 2756A-TS 6-bp allele combination was significantly higher in RPL. Based on these results, we propose that the MTR 2756AA genotype and MTR 2756A-TS 6-bp allele combination are possible predisposing factors for RPL development in Korean women.

Common polymorphisms in the P-selectin gene in women with recurrent spontaneous abortions

BackgroundTo investigate possible associations of P-selectin polymorphisms with idiopathic recurrent pregnancy loss (RPL). MethodsStudy subjects comprised 270 consecutive RPL cases attending outpatient maternity services, and 322 multi-parous control women. P-selectin genotyping was done by PCR-RFLP and PCR-ASA methods. ResultsThe P-selectin variants rs1800807, rs1800805, and rs6127, were in Hardy Weinberg equilibrium, and low linkage disequilibrium was noted between the three studied SNPs. The frequency of rs6127 A allele (P<0.001I), but not rs1800807 C allele (P=0.957) or rs1800805 A allele (P=0.760), was higher in RPL cases than in control women. Significant differences in the distribution of rs6127 (P<0.001), but not rs1800807 (P=0.444) or rs1800805 (P=0.391) genotypes were seen between cases and controls, and only rs6127 showed a significant association with RPL, with increments of 2.65 and 4.96 in disease risk seen for heterozygous and homozygous carriers, respectively. Among the 8 three-locus Pselectin haplotypes constructed (rs1800807/rs1800805/rs6127), increased frequency of GGG (Pc=0.0249), CGG (Pc=0.0256), and CAG (Pc=0.0174) haplotypes, and lower frequency of CGA haplotype (Pc=0.0091) were seen in RPL cases, thus conferring disease susceptibility and protective nature to these haplotypes, respectively. ConclusionsP-selectin gene polymorphisms and haplotypes contribute to RPL development.

Association of inherited thrombophilia with embryonic and postembryonic recurrent pregnancy loss

To investigate the impact of maternal-inherited thrombophilia: effects of factor V Leiden (FVL) and prothrombin gene mutation (FII 20210G>A) on the development of recurrent pregnancy loss in embryonic and postembryonic periods. A total of 153 patients were analysed for FVL and FII 20210G>A according to placenta gestation: 94 women with embryonic loss prior 10 weeks of gestation and 59 women with postembryonic (early fetal) loss occurring between 10 and 14 weeks of gestation. The control group consisted of 100 healthy women, with at least one uncomplicated full-term pregnancy. FVL prevalence was not significantly associated with pregnancy loss prior to 10 weeks of gestation (9.6%) compared with controls (7%) [odds ratio (OR) 1.41; 95% confidence interval (CI) 0.454-4.416, P > 0.05], but it was much more pronounced in women with postembryonic loss (10-14 weeks of gestation) - 18.6% (OR 3.05; 95% CI 1.010-9.387, P = 0.047). FII 20210G>A was significantly higher in both groups with embryonic (17%) and early fetal losses (16.9%) as compared to controls (3%) (OR 6.63; 95% CI 1.731-29.752, P = 0.003; OR 6.60; 95% CI 1.572-31.856, P = 0.006). FII 20210G>A is significantly associated with an increased risk of early recurrent pregnancy loss throughout the entire first trimester. FVL was significantly higher only in early fetal period after starting of the placentation process, but not associated with embryonic recurrent pregnancy loss. These results suggested that the first trimester should be viewed rather as a heterogeneous interval, with different relation to FVL in the embryonic and postembryonic fetal period. Genetic testing should be applied according to the diverse contribution of thrombophilic markers to embryonic and postembryonic period.

Association of endothelial protein C receptor haplotypes, factor V Leiden and recurrent first trimester pregnancy loss

Objectives We evaluated whether the endothelial protein C receptor (EPCR) haplotypes A1 and A3 exert effects on the development of recurrent pregnancy loss (RPL) in association with factor V Leiden. Design and methods We determined the EPCR haplotypes A1 and A3 and factor V Leiden in 49 women with a history of RPL and 48 parous controls. Results In carriers of factor V Leiden the A1 haplotype decreased the relative risk for RPL from 2.2 to 1.0. Conclusions The EPCR A1 haplotype tends to modulate the risk for RPL in carriers of factor V Leiden.