Maternal homocysteine and folate levels and risk of recurrent spontaneous abortion: A meta-analysis of observational studies

Genetic polymorphisms in folate metabolism and their association with recurrent spontaneous abortion

OBJECTIVE

This study aims to investigate the relationship between polymorphisms in key enzyme genes involved in folate metabolism and recurrent spontaneous abortion (RSA).

METHODS

Genotypic data and red blood cell folate levels were collected from 150 patients with RSA and 120 healthy controls. The genotype and allele frequency distribution at the methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C, and methionine synthase reductase (MTRR) A66G loci were analyzed and compared. Additionally, homocysteine levels were measured.

RESULTS

Significant differences in genotype and allele frequencies were observed between the RSA group and the control group at the MTHFR C677T and MTRR A66G loci. Specifically, the distribution of genotypes and alleles at the MTHFR C677T locus showed a marked divergence between the two groups. In the RSA group, the frequency of the TT genotype was notably higher compared to the control group, suggesting a potential association with an increased risk of recurrent spontaneous abortion. Similarly, at the MTRR A66G locus, the AG and GG genotypes were more prevalent in the RSA group than in the control group, further implicating these genetic variants in the pathogenesis of RSA.

CONCLUSION

We identified a significant association between the TT genotype of MTHFR C677T and reduced red blood cell folate concentration. Additionally, the AG and GG genotypes of MTRR A66G were found to be linked to an increased risk of RSA. These findings suggest that specific variants in genes encoding folate metabolism enzymes may contribute to the risk of recurrent spontaneous abortion.

Homocysteine induces endometrial ferroptosis via MAPK pathway in recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) with complex etiology and elevated homocysteinemia (HCY) has been recognized one of the risk factors, however the mechanism of HCY participation in RPL are not fully elucidated.

METHODS

Samples from RPL_HHCY, RPL_NHCY and controls were used to metabolomics and proteomic analysis. Cell counting kit-8 assay, EdU assay kit, wound healing assay and induced decidualization were performed to observe the HCY induced dysfunction of human endometrial stromal cells (hESCs). Intracellular ROS, lipid peroxidation, MDA, GSH and Fe2+ were examined. Western blotting was used to measure protein expression.

RESULTS

We found differential metabolites were enriched in glutathione metabolism, and differentially protein expression were enriched in the ferroptosis. In vitro, ferrostatin-1 (Fer-1) could improve the decrease of HCY induced cell viability, proliferation, migration and decidualization of hESCs, and reverse ROS, lipid peroxidation, MDA, GSH and Fe2+ levels. Also, Fer-1 enhanced GPX4 and SLC3A2, lightened ACSL4 protein expression. Gene Set Variation Analysis (GSVA) found MAPK is an important pathway for ferroptosis, and inhibition MAPK signaling pathway reversed the phosphor-ERK (p-ERK), p-JNK and p-P38 amplified by HCY.

CONCLUSIONS

Our findings implicate that HCY disturbs the function of hESCs by activation of the MAPK signaling pathway induced ferroptosis and may contribute to RPL. This provides a theoretical basis for the relationship between high HCY and RPL.

Distribution of polycystic ovary syndrome (PCOS) phenotypes in Iranian women: a cross-sectional study

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by diverse clinical and metabolic manifestations. This study aimed to investigate the prevalence of PCOS phenotypes and their association with hematological, biochemical, and hormonal parameters in PCOS, with a particular focus on infertile women and those with recurrent pregnancy loss (RPL).

RESULTS

Phenotype A was the most prevalent phenotype overall and within both infertile and RPL subgroups. However, no significant differences in hematological, biochemical, or hormonal parameters were observed among the PCOS phenotypes, except for lower RBC and hematocrit levels in phenotype F. PCOS women with RPL demonstrate significantly lower levels of RBC, hemoglobin, and hematocrit in phenotype F.

Homocysteine and Multiple Health Outcomes: An Outcome-Wide Umbrella Review of Meta-analyses and Mendelian Randomization Studies

Elevated levels of homocysteine (Hcy) are associated with various health outcomes. We aimed to systematically assess the credibility and certainty of evidence of associations of Hcy and Hcy-lowering therapies with various health outcomes. We retrieved observational meta-analyses examining the associations between Hcy and health outcomes, interventional meta-analyses investigating health outcomes related to Hcy-lowering treatments, and Mendelian randomization (MR) studies exploring the causal associations of Hcy with health outcomes to perform an umbrella review. A total of 135 observational meta-analyses, 106 MR studies, and 26 interventional meta-analyses were included. Among observational studies, 10 associations of diseases/outcomes were classified as highly suggestive; only 1 outcome (digestive tract cancer) was supported by convincing evidence (class I; odd ratio = 1.27, 95% confidence interval = 1.16, 1.40; P = 6.79 × 10-7; I2 = 0, 95% prediction interval excluding null, >1000 cases; P > 0.1 for tests of both small-study effects and excess significance bias). In MR studies, 5 outcomes associated with Hcy presented robust evidence (P < 0.01, power >80%). Among 25 outcomes explored by both observational meta-analyses and MR studies, 7 had consistent results, indicating that elevated Hcy is causally associated with an increased risk of these outcomes. The 3 types of studies collectively suggested that the association of stroke with Hcy was supported by observational studies, causally by MR studies, and further validated by intervention meta-analyses showing that Hcy-lowering with folic acid significantly reduced risk of stroke. For dementia and colorectal cancer, Hcy was significantly associated in meta-analyses of observational studies and folic acid decreased disease risks in interventional meta-analyses. The current umbrella review indicates that convincing evidence for a definitive role of Hcy exposure solely exists in the context of digestive tract cancer excluding bias; however, Hcy may not be causal for this disease. All the 3 types of studies collectively support that Hcy is a key causal risk factor, and Hcy-lowering (specifically with folic acid) may serve as an effective intervention for stroke. This trial was registered at PROSPERO as CRD42024541335.

Association between diabetes mellitus and miscarriage, recurrent miscarriage: A meta-study

BACKGROUND

Previous studies provided inconsistent associations between diabetes mellitus (DM) and miscarriage, recurrent miscarriage (RM). Therefore, this study aims to evaluate the association between DM and miscarriage, specifically RM, through a meta-analysis approach.

METHODS

We searched for articles published before July 2023 in PubMed and Web of Science databases. STATA 12.0 software was used to compute all the results collected from included studies.

RESULTS

DM was associated with a higher risk of miscarriage, RM (miscarriage: odds ratio [OR]/relative risk [RR] = 1.23, 95% confidence interval [CI] 1.13 to 1.34; RM: OR/RR = 1.73, 95% CI 1.55 to 1.94). T1DM was associated with a higher risk of miscarriage (OR/RR = 1.16, 95% CI 1.07 to 1.26). Similarly, T2DM showed a higher risk of miscarriage (OR/RR = 1.44, 95% CI 1.23 to 1.68). Miscarriage, RM were associated with a higher risk of DM (miscarriage: OR/RR = 1.14, 95% CI 1.08 to 1.19; RM: OR/RR = 1.14, 95% CI 1.08 to 1.20). Furthermore, miscarriage was found to be associated with a higher risk of T2DM (OR/RR = 1.08, 95% CI 1.05 to 1.11).

CONCLUSION

In conclusion, our meta-analysis findings indicate a significant association between DM and miscarriages as well as RM. As a result, women with a history of miscarriage should consider regular monitoring of their metabolic health as a potential benefit. Nevertheless, it is important to note that further research is needed to validate the results of our study and shed light on the biological mechanisms underlying these associations.

Effect of extended precision nursing on neurobehavioral function and pregnancy outcome in patients with threatened abortion

This study aimed to assess the impact of continuous precision nursing on neurobehavioral function and pregnancy outcomes in patients experiencing threatened abortion. A total of 130 patients with early threatened abortion admitted to our hospital between October 2020 and January 2023 were selected and categorized into 2 groups based on intervention methods. The control group received routine nursing intervention, whereas the observation group received continuous precision nursing intervention. Changes in affective status scores, SF-36 scores, knowledge mastery scores, and satisfaction scores in the neurobehavioral function test before and after intervention were recorded in both groups. Additionally, pregnancy outcomes, obstetric adverse reaction rates, and neonatal conditions were documented. Following intervention, scores for tension-anxiety, depression-dejection, anger-hostility, vigor-activity, fatigue-inertia, and confusion-bewilderment gradually decreased in both groups, with significantly lower scores observed in the observation group compared to the control group (P < .05). SF-36 scores in 8 dimensions, including physical functioning, role-physical, bodily pain, and overall health rating, showed a gradual increase in both groups, with the observation group scoring higher than the control group (P < .05). Knowledge mastery and satisfaction scores also increased significantly after intervention, with the observation group surpassing the control group (P < .05). The observation group exhibited lower rates of abortion and premature birth, along with a higher rate of full-term pregnancy compared to the control group, with statistically significant differences (P < .05). Furthermore, the observation group displayed lower rates of adverse reactions and low birth weight infants, with significant differences compared to the control group (P < .05). No significant differences were observed in neonatal mortality and neonatal intensive care unit transfer rates between the observation and control groups (P > .05). Continuous precision nursing contributes to improved pregnancy outcomes for patients with threatened miscarriage within the first 12 weeks of pregnancy. This comprehensive care approach is associated with enhanced knowledge retention, protection of neurological function, and an overall improvement in quality of life.

Association between early spontaneous abortion and homocysteine metabolism

Objective

The purpose of this study is to explore the effects of homocysteine (HCY) metabolism and related factors on early spontaneous abortion.

Methods

We conducted a hospital-based case-control study and included a total of 500 cases and 1,000 controls in Shaanxi China. Pregnant women waiting for delivery in the hospital were interviewed to report their characteristics and other relevant information during pregnancy. The unconditional Logisitic regression model was applied to assess the association between early spontaneous abortion and HCY metabolism and related factors. The multiplicative model was applied to assess the effects of interaction of HCY metabolism and related factors on early spontaneous abortion. The logit test method of generalized structural equation model (GSEM) was used to construct the pathway diagram of HCY metabolism and related factors affecting early spontaneous abortion.

Results

Folic acid supplementation and adequate folic acid supplementation during periconception were the protective factors of early spontaneous abortion (OR = 0.50, 95% CI: 0.38-0.65; OR = 0.44, 95% CI: 0.35-0.54). The serum folate deficiency, higher plasma HCY in early pregnancy, the women who carried the MTHFR 677TT genotype were the risk factors of early spontaneous abortion (OR = 5.87, 95% CI: 1.53-22.50; OR = 2.94, 95% CI: 1.14-7.57; OR = 2.32, 95% CI: 1.20-4.50). The women's educational level and maternal and child health care utilization affected the occurrence of early spontaneous abortion by influencing the folic acid supplementation during periconception. The folic acid supplementation during periconception affected the occurrence of early spontaneous abortion by influencing the level of serum folate or plasma HCY in early pregnancy. The maternal MTHFR 677 gene polymorphism affected the occurrence of early spontaneous abortion by influencing the level of serum folate in early pregnancy. In terms of the risks for early spontaneous abortion, there was multiplicative interaction between higher plasma HCY in early pregnancy, serum folate deficiency in early pregnancy and maternal MTHFR 677TT genotype (OR = 1.76, 95% CI: 1.17-4.03), and there was multiplicative interaction between higher plasma HCY and serum folate deficiency in early pregnancy (OR = 3.46, 95% CI: 2.49-4.81), and there was multiplicative interaction between serum folate deficiency in early pregnancy and maternal MTHFR 677TT genotype (OR = 3.50, 95% CI: 2.78-5.18). The above interactions are all synergistic. The occurrence risk of early spontaneous abortion was significantly increased if multiple factors existed at the same time.

Conclusion

Our study is the first time to construct the pathway of HCY metabolism and related factors affecting early spontaneous abortion, and provides a comprehensively new idea to prevent and reduce the occurrence of spontaneous abortion.

Association between eNOS gene polymorphisms and the risk of unexplained recurrent spontaneous abortion in Yunnan province, China

BACKGROUND

Recurrent spontaneous abortion affects approximately 1-2% of reproductive-age women, with roughly half of RSA cases classified as unexplained recurrent spontaneous abortion (URSA). Genetic polymorphisms in eNOS gene have been shown to have significant implications across various disease processes. Nevertheless, the potential impact of eNOS gene polymorphisms on the susceptibility to URSA in Yunnan population has yet to be explored or documented.

OBJECTIVE

This study aims to investigate the potential association between specific variations in the eNOS gene (VNTR 4b/a, -786T > C, and +894G > T) and the risk of URSA in Yunnan population.

METHODS

A total of 243 URSA patients and 241 healthy females are involved in this study. We conducted amplification of the eNOS gene fragment and performed sanger sequencing to detect the specific eNOS gene polymorphisms, including VNTR 4b/a, -786T > C, and +894G > T. Using a multivariate logistic regression model, we evaluate the potential association between eNOS gene polymorphisms (VNTR 4b/a, -786T > C, and +894G > T) and the risk of URSA. Furthermore, serum NO levels were measured in URSA patients.

RESULTS

The presence of VNTR 4a, -786C, and +894T alleles was found to be associated with an increased risk of URSA. Additionally, our study revealed a significant association between the G-C-4b haplotype of the investigated eNOS gene polymorphisms and a predisposition to URSA. Notably, these eNOS polymorphisms were shown to reduce serum NO levels in URSA patients.

CONCLUSION

This study provides evidence supporting the association between eNOS gene polymorphisms, VNTR 4b/a, -786T > C, and +894G > T, and the occurrence of URSA in Yunnan Province, China.

Insulin resistance in women with recurrent miscarriage: a systematic review and meta-analysis

PURPOSE

This review aimed to investigate the association of insulin resistance (IR) in women with recurrent pregnancy loss compared to women with normal pregnancy history.

METHODS

PubMed, EMBASE, the Web of Science and Google Scholar databases were accessed to collect published observational studies that compared IR of recurrent pregnancy loss women with healthy women until the 6^th of October 2022. Outcomes assessed in this review and meta-analysis included fasting blood glucose, fasting plasma insulin, homeostasis model assessment for IR, glucose to insulin ratio. Mean differences, odds ratios with 95% confidence interval were pooled using the fixed or random effect models. Sensitivity analyses were performed to validate the robustness of the results. Review Manager version 5.4.1 and Stata version 8.0 were used.

RESULTS

A total of nineteen studies involving 4453 individuals were included. Recurrent pregnancy loss patients presented significantly higher fasting blood glucose, fasting plasma insulin, homeostasis model assessment for IR, and lower glucose to insulin ratios. Additionally, recurrent pregnancy loss patients had higher rates of IR as defined by abnormal fasting plasma insulin, homeostasis model assessment for IR, and glucose to insulin ratio. Sensitivity analyses validated the robustness of the results.

CONCLUSION

In the current review, we show that recurrent pregnancy loss is associated with a higher degree of IR and highlight the importance of screening and treatment of IR.

The effect of low-molecular-weight heparin on live birth rate of patients with unexplained early recurrent pregnancy loss: A two-arm randomized clinical trial

BACKGROUND

The effect of anticoagulant medication in unexplained early recurrent pregnancy loss (RPL) patients is controversial. This clinical trial evaluated the effect of low-molecular-weight heparin (LMWH) on pregnancy outcomes in these patients.

MATERIALS AND METHODS

The study was performed as a single-blind randomized clinical trial between 2016 and 2018. Samples were selected from patients who were referred to Avicenna RPL clinic with a history of at least two previously happened early unexplained miscarriages. The eligibility was defined strictly to select unexplained RPL patients homogenously. One hundred and seventy-three patients who got pregnant recently were allocated randomly into two groups LMWH plus low-dose aspirin treatment (Group A = 85) and low-dose aspirin treatment only (Group B = 88)) and were followed up till their pregnancy termination (delivery/abortion). A per-protocol analysis was carried out and all statistical tests were two-sided with a P < 0.05 significance level.

RESULTS

The live birth rates (LBRs) in Groups A and B were 78% and 77.1%, respectively, which did not show any statistically significant difference between the two groups, neither in rates nor in time of abortion. In subgroup analysis for polycystic ovary syndrome (PCOS) patients, the odds ratio for study outcome (intervention/control) was 2.25 (95% confidence interval: 0.65-7.73). There was no major adverse event whereas minor bleeding was observed in 18% of patients in Group A.

CONCLUSION

LMWH does not improve the LBR in unexplained RPL patients, however, it is recommended to evaluate its effect separately in PCOS patients.

Effect of Blood Homocysteine on the Outcome of Artificial Insemination in Women with Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is the major reason for women's low fertility and the most frequent endocrine disorder in women of childbearing age. Homocysteine is an amino acid that contains sulfur that has been negatively correlated with the reproductive outcome of polycystic women treated with IVF/ICSI. However, the impact of blood homocysteine levels on the outcome of artificial insemination in polycystic ovary syndrome women is unknown. The goal of this study is to examine the impact of serum homocysteine on the result of intrauterine insemination in females who have polycystic ovary syndrome (PCOS).

Methods

96 infertile women (129 cycles) treated with artificial insemination were collected, including 66 cases (87 cycles) in the case group (PCOS group) and 30 cases (42 cycles) in the control group (male factor infertility). The differences in general data amongst two groups, such as BMI, Hcy, and age, were compared. The case group has been classified into two groups based on serum Hcy level: LHcy group (Hcy < 15) and HHcy group (Hcy ≥ 15). The relationship among pregnancy and serum Hcy level outcome in PCOS women was compared.

Results

The PCOS group had substantially increased serum homocysteine levels in comparison to the control group (P = 0.019). Among PCOS women, the clinical pregnancy rates of artificial insemination in the HHcy group and LHcy group were 14.29% and 37.88%. The difference among the two groups was substantial (P = 0.044). Artificial insemination frequency, ovulation induction, BMI, infertility years, AMH, serum testosterone, HOME IR, TSH, TPOAb, hCG, daily follicle size, intimal thickness, and other factors did not differ greatly between the two groups.

Conclusion

Serum homocysteine levels are increased in women having PCOS. Their levels above the threshold will lower the clinical pregnancy rate of intrauterine insemination in PCOS women.

Association between serum vitamin D level during pregnancy and recurrent spontaneous abortion: a systematic review and meta-analysis

PROBLEM

Previous studies had shown that there might be an association between serum vitamin D concentrations and the occurrence of recurrent spontaneous abortion (RSA). However, the conclusions remained controversial. The objective of this study was to systematically review the evidence for an epidemiological association between vitamin D and RSA.

METHOD OF STUDY

The literature search was performed in the following databases: PubMed, Web of Science, Embase and Chinese databases. The I² statistic was used to evaluate heterogeneity. Effect sizes were calculated using fixed or random effects models, including standardized mean difference (SMD), odds ratios (OR) and their 95% confidence intervals (95%CI). Then we performed subgroup analysis, sensitivity analysis and publication bias analysis.

RESULTS

Fourteen studies from five countries were included. Based on the results, patients with RSA had lower vitamin D levels than controls (SMD = -1.48, 95%CI: -2.01, -0.94, P<0.001), and pregnant women with vitamin D deficiency (VDD) had a higher risk of developing RSA (OR = 4.02, 95%CI: 2.23, 7.25, P<0.001). There was remarkable heterogeneity between studies (I² _SMD = 97.3%, P<0.001; I² _OR = 82.2%, P<0.001). The results of the subgroup analysis suggested that heterogeneity may be caused by the assay method, age and region. Sensitivity analysis showed the analysis results were robust.

CONCLUSION

Patients with RSA had lower serum vitamin D levels than normal pregnant women, and pregnant women with VDD might be at higher risk for RSA. This article is protected by copyright. All rights reserved.