Association between vascular endothelial growth factor polymorphism and recurrent pregnancy loss: A systematic review and meta-analysis

Angiogenic factors and the lectin pathway of complement in women with secondary recurrent pregnancy loss

The poor remodeling of placental spiral arteries seen in preeclampsia is also discussed to contribute to recurrent pregnancy loss (RPL) preceded by abnormal angiogenesis and excessive complement activation. Low levels of Mannose-binding-lectin (MBL), a pattern recognition molecule (PRM) of the lectin pathway, have been found in women with RPL. We propose that pregnancy loss is connected to defective angiogenesis with reperfusion damage in the placenta and decreased levels of PRM in the lectin pathway in women with RPL. In this cohort study, we investigate the angiogenic factors and the lectin complement pathway in early pregnancy and their time-dependent relationship with pregnancy outcomes in 76 women with secondary RPL (sRPL) who have at least four prior pregnancy losses and a live birth. We evaluated levels of Angiopoietin-1 (Ang-1), Angiopoietin-2 (Ang-2), Vascular Endothelial Growth Factor (VEGF), soluble fms-like tyrosine kinase-1 (sFlt-1), and the PRMs, MBL, ficolin-1, -2, -3 and an additional soluble PRM, Pentraxin-3, during the 5th, 6th, and 7th gestational weeks. Our results showed that, compared to live births, pregnancies that ended in loss were associated with elevated VEGF levels and decreased levels of the Ang-2/Ang-1 ratio. Also, increasing levels of ficolin-2 were significantly associated with pregnancy loss, with MBL showing no association. Our research suggests that women with sRPL may have inadequate placentation with impaired angiogenesis in pregnancies ending in a loss.

Beta-Meta: a meta-analysis application considering heterogeneity among genome-wide association studies

Many packages for a meta-analysis of genome-wide association studies (GWAS) have beendeveloped to discover genetic variants. Although variations across studies must be considered, there are not many currently-accessible packages that estimate between-study heterogeneity. Thus, we propose a python based application called Beta-Meta which can easilyprocess a meta-analysis by automatically selecting between a fixed effects and a randomeffects model based on heterogeneity. Beta-Meta implements flexible input data manipulation to allow multiple meta-analyses of different genotype-phenotype associations in asingle process. It provides a step-by-step meta-analysis of GWAS for each association inthe following order: heterogeneity test, two different calculations of an effect size and ap-value based on heterogeneity, and the Benjamini-Hochberg p-value adjustment. Thesemethods enable users to validate the results of individual studies with greater statisticalpower and better estimation precision. We elaborate on these and illustrate them with examples from several studies of infertility-related disorders.

Effect of autologous platelet-rich plasma for treatment of recurrent pregnancy loss: a randomized controlled trial

Objective

Recurrent pregnancy loss (RPL) is a fertility problem for which no exact mechanism of abortion or efficient treatment has been described. This study was conducted between 2018 and 2019 to investigate the effectiveness of autologous platelet-rich plasma (PRP) in improving the live birth rate of women with RPL who required in vitro fertilization (IVF).

Methods

A total of 63 patients with at least two previous pregnancy losses and no specific cause detected for the RPL were included and randomly assigned into two groups (PRP and control). Intrauterine infusion of 0.5 mL of autologous PRP was performed 48 hours before embryo transfer in the PRP group. Women in the control group received standard treatment.

Results

Forty patients completed the study. The baseline and cycle characteristics of the participants did not differ significantly between the PRP and control groups. The clinical pregnancy rate was higher in the PRP group (35% vs. 20%, P=0.288). The live birth rate was 15% in the PRP group, but no live births were recorded in the control group (P=0.231).

Conclusion

This is the first study to show that intrauterine infusion of PRP in patients with RPL who undergo IVF may increase the chance of live birth.

The Role of Interleukins in Recurrent Implantation Failure: A Comprehensive Review of the Literature

Recurrent implantation failure (RIF) is a multifactorial condition affecting 10-15% of in vitro fertilization (IVF) couples. Data suggest that functional dysregulation of the endometrial immune system constitutes one of the main pathophysiological mechanisms leading to RIF. The aim of this article is to provide a thorough presentation and evaluation of the role of interleukins (ILs) in the pathogenesis of RIF. A comprehensive literature screening was performed summarizing current evidence. During implantation, several classes of ILs are secreted by epithelial and stromal endometrial cells, including IL-6, IL-10, IL-12, IL-15, IL-18, and the leukemia inhibitory factor. These ILs create a perplexing network that orchestrates both proliferation and maturation of uterine natural killer cells, controls the function of regulatory T and B cells inhibiting the secretion of antifetal antibodies, and supports trophoblast invasion and decidua formation. The existing data indicate associations between ILs and RIF. The extensive analysis performed herein concludes that the dysregulation of the ILs network indeed jeopardizes implantation leading to RIF. This review further proposes a mapping of future research on how to move forward from mere associations to robust molecular data that will allow an accurate profiling of ILs in turn enabling evidence-based consultancy and decision making when addressing RIF patients.

Polymorphisms of vascular endothelial growth factor and recurrent implantation failure: a systematic review and meta-analysis

PURPOSE

To investigate the associations between polymorphisms of vascular endothelial growth factor (VEGF) with recurrent implantation failure (RIF).

METHODS

We performed the systematic review and meta-analysis by searching databases of PubMed, EMBASE, OVID, and CNKI (China National Knowledge Infrastructure) for studies that evaluated the associations between VEGF polymorphisms with RIF. Meta-analysis was performed if the polymorphism was studied by more than two case-control studies. Data were analyzed using R software. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported to assess the associations.

RESULTS

Nine VEGF polymorphisms (-1154G > A, -460T > C, +405G > C, -7C > T, -634C > G, -2578C > A, +936C > T, 5C > T, -583C > T) were systematically reviewed. Meta-analysis was performed on VEGF -1154 G > A polymorphism. Three case-control studies consisted of 683 women were included in the quantitative meta-analysis (305 RIF patients and 378 controls). Results showed that VEGF -1154A allele was significantly associated with RIF (OR 1.39, 95% CI 1.08-1.78, P-value = 0.01). The dominant genetic model showed that VEGF 1154AA plus VEGF 1154AG genotypes were more frequent in RIF patients than VEGF 1154GG genotype (OR 1.56, 95% CI 1.10-2.20, P-value = 0.01). However, the result under the recessive genetic model showed no significant difference (OR 1.67, 95% CI 0.92-3.03, P-value = 0.09).

CONCLUSION

VEGF -1154A allele may serve as one of the predisposing factors of RIF. Women with VEGF 1154 AA/GA genotypes were at higher risk of RIF. However, we should consider the haplotype effect of VEGF polymorphisms in future studies.

Association of vascular endothelial growth factor polymorphisms with polycystic ovarian syndrome risk: a meta-analysis

BACKGROUND

Polycystic ovarian syndrome (PCOS) is a multi-gene hereditary disorder caused by the interaction of certain gene variation with environmental factors. Previous studies have shown that vascular endothelial growth factor (VEGF) gene polymorphisms are associated with the risk of polycystic ovarian syndrome. However, the results of these studies remain controversial. We performed the present meta-analysis aiming to further investigate the potential relationship between VEGF polymorphisms and susceptibility to PCOS.

METHODS

The following databases were systematically searched: PubMed, EMBASE, Web of Science (WOS), China National Knowledge Infrastructure (CNKI), and Wanfang Databases. The correlation between VEGF polymorphisms and PCOS risk was assessed by calculating pooled odds ratios (ORs) and their 95% confidence intervals (95% CIs). Subgroup analyses stratified by ethnicity and source of control were also conducted. Besides, trial sequential analysis (TSA) was done to verify the reliability of the pooled results.

RESULTS

10 relevant case-control studies were incorporated in this meta-analysis, involving 1347 PCOS cases and 1378 controls. The VEGF rs2010963 polymorphism was associated with decreased PCOS risk in the whole population and the Asian populations. The VEGF rs3025039 polymorphism was associated with decreased PCOS susceptibility and the Asian populations, but increased risk of PCOS was observed among the Caucasian populations. In addition, the results of trial sequential analysis (TSA) showed the negative correlation between rs2010963 and PCOS risk, obtained by our meta-analysis, was stable and reliable.

CONCLUSION

Overall, different VEGF gene polymorphisms may exert different effects on PCOS susceptibility. The VEGF rs2010963 polymorphism decreases PCOS susceptibility in both the whole population and the Asian populations, and VEGF rs3025039 polymorphism causes lower PCOS susceptibility in the whole population and the Asian populations but higher in the Caucasian populations.

Association of vascular endothelial growth factor A polymorphisms and aberrant expression of connexin 43 and VEGFA with idiopathic recurrent spontaneous miscarriage

AIM

Idiopathic recurrent spontaneous miscarriage (IRSM) is one of the pregnancy outcomes that affects 1-2% of women trying to conceive. Specific genotype or aberrant expression of vascular endothelial growth factor A (VEGFA) and connexin 43 (Cx43) as two important genes for embryonic development are deemed to increase the risk of IRSM.

METHODS

To investigate any possible association of VEGFA polymorphisms and aberrant expression of Cx43 and VEGFA with IRSM, we carried out a case-control study including embryo chorionic villus tissues of 100 pregnant women with IRSM and 100 embryo chorionic villus tissues of healthy pregnant women without history of miscarriage. Restriction fragment length polymorphism was used for genotyping of rs699947 (-2578C/A) and rs2010963 (-634G/C) polymorphisms in VEGFA. Besides, quantitative real-time PCR was performed for VEGFA and Cx43 expression analysis.

RESULTS

The results showed that the frequency of -634G/C and C/C genotypes was significantly higher in aborted fetuses (P = 0.001 and P < 0.001, respectively) compared to the control group's. However, the frequency of -2578C/A genotypes was not significantly different between the cases and controls. Moreover, a significant higher expression of VEGF (P = 0.0005) and Cx43 (P = 0.0011) was observed in chorionic villus tissues of women with IRSM.

CONCLUSION

The finding demonstrated that IRSM frequency may depend on GC and CC genotypes of rs2010963 VEGF polymorphism and expression level of VEGF and Cx43 in IRSM patients was increased.

Dysregulation of inflammatory cytokines and inhibition of VEGFA in the human umbilical cord are associated with negative pregnancy outcomes

INTRODUCTION

Cytokines and vascular endothelial growth factors (VEGF) are involved in all aspects of pregnancy: from placentation, through fetal development, parturition and neonatal well-being. Umbilical cord inflammatory cytokines and/or VEGF have not been well studied with respect to dysregulation associated with disorders of pregnancy or maternal/neonatal outcomes.

METHODS

Here we have used multiplex ELISA to screen umbilical cord lysates (comprising cord blood, endothelia and Wharton's jelly, n = 380), for levels of IFN-γ, IL1-β, IL-6, IL-8, IL-10, TNF-α and VEGFs A, C and D and associations with 46 ICD9/10 codes encompassing obstetric, maternal and neonatal variables.

RESULTS

No significant differences were observed for IFNγ, VEGFC or VEGFD with any clinical outcomes. The cytokines IL1-β, IL-6, IL-8, IL-10, and TNF-α showed varying levels of induction and suppression with primarily fetal-placental and neonatal complications. The largest number of significant differences between umbilical cytokines and clinical outcomes were observed for chorioamnionitis (IL1-β, IL-6, IL-8, TNF-α), and meconium passage during birth (IL1-β, IL-6, IL-8) where significant pro-inflammatory responses occurred and sex differences in IL-8 expression were noted. In contrast, gonococcal infection showed suppressed immune response significantly lowering IL1-β, IL-6, IL-8, IL-10 and TNF-α. For 12/46 negative pregnancy outcomes, strong suppression of VEGFA occurred.

DISCUSSION

Angiogenic and inflammatory changes in the umbilical cord could be detrimental by increasing vascular permeability in the umbilical artery or vein and/or altering vascular tone, either of which would alter blood flow affecting delivery and removal of compounds. Further elucidation of inflammatory responses in the umbilical cord may provide mechanistic understanding of adverse pregnancy outcomes.

3'-UTR Polymorphisms in the Vascular Endothelial Growth Factor Gene (VEGF) Contribute to Susceptibility to Recurrent Pregnancy Loss (RPL)

Numerous studies have examined the genetic association of vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) with recurrent pregnancy loss (RPL). However, of the four known SNPs in the 3′-untranslated region (3′-UTR) of VEGF, three SNPs—namely rs3025040 (1451C>T), rs10434 (1612G>A), and rs3025053 (1725G>A)—remain poorly characterized with regard to RPL. Herein, we evaluated the association between these three SNPs in the VEGF 3′-UTR and RPL susceptibility. We analyzed VEGF 3′-UTR gene variants in with and without RPL using TaqMan allelic discrimination. There were significant differences in the genotype frequencies of 1612G>A (GA: adjusted odds ratio (AOR), 0.652; 95% confidence interval (CI), 0.447–0.951; p = 0.026) and 1725G>A (GA: AOR, 0.503; 95% CI, 0.229–0.848; p = 0.010) in RPL patients vs. controls. Our results indicate that the 1612G>A and 1725G>A polymorphisms in the 3′-UTR of VEGF are associated with RPL susceptibility in Korean women. These data suggest that VEGF 3′-UTR polymorphisms may be utilized as biomarkers for the detection of RPL risk and prevention.

Association between sperm DNA fragmentation and idiopathic recurrent pregnancy loss: a systematic review and meta-analysis

Sperm DNA fragmentation (sDF) has emerged as a valuable tool for evaluating male fertility, yet the relationship between DNA fragmentation in the male gamete and idiopathic recurrent pregnancy loss (RPL) remains a topic of ongoing debate. Hence, a meta-analysis was conducted of 12 prospective and 2 retrospective studies involving 530 men with a history of RPL who underwent sDF testing compared with 639 fertile control participants. The main outcome measures were sDF measured by comet assay, TdT (terminal deoxynucleotidyl transferase)-mediated dUDP nick-end labelling (TUNEL), sperm chromatin dispersion (SCD) or sperm chromatin structure assay. Overall, couples with a history of idiopathic RPL demonstrated higher levels of sDF than fertile couples (average mean difference 11.98, P < 0.001). Subgroup analysis demonstrated a similar average mean difference between the RPL and control groups using SCD compared with TUNEL, while mean paternal age and mean sperm motility in the RPL groups tested by meta-regression demonstrated no significant effect on the mean differences in sDF (P > 0.10). These results support the diagnostic value of sDF over standard semen analysis, as well as a possible paternally derived genetic origin of unexplained RPL. Further prospective studies are required to further assess the predictive utility of sDF for assessing couples with unexplained RPL.