Role of miRNA polymorphism in recurrent pregnancy loss: a systematic review and meta-analysis

There are a plethora of publications on the role of miRNA gene polymorphism and its association with recurrent pregnancy loss (RPL), but a lack of uniformity in the studies available due to the variable subject population, heterogeneity and contrary results of significance. Rigorous data mining was done through PubMed, SCOPUS, Cochrane library, Elsevier and Google Scholar to extract the studies of interest published until June 2021. A total of eight SNPs of miRNAs have been included, where >= 2 studies per SNPs were available. Analysis was done on the basis of pooled odds ratios and 95% CI. This is the first meta-analysis on miRNA SNPs in RPL that suggests that rs11614913, rs3746444 and rs2292832 biomarkers may decrease the risk of RPL under different genetic models. Lay abstract miRNAs play a crucial role in the regulation of several biological processes and have an important role in recurrent pregnancy loss (RPL), proven by many studies. However, the results from these studies are highly inconsistent, prompting us to undertake the meta-analysis to explore the real association between different miRNAs and their SNPs, with a risk of spontaneous abortions/RPL. The impetus for conducting this meta-analysis was to obtain a more robust picture of the association between miRNA polymorphism and RPL risk. This study will aid the development of a biomarker panel in the future, for the early diagnosis and prognosis of RPL patients.