Association study of microRNA polymorphisms with risk of idiopathic recurrent spontaneous abortion in Korean women

The aim of this study was to investigate the association of microRNA polymorphisms (miR-146aC>G, miR-149T>C, miR-196a2T>C, and miR-499A>G) in Korean patients with recurrent spontaneous abortion (RSA). We conducted a case–control study of 564 Korean women: 330 patients with at least two unexplained consecutive pregnancy losses and 234 healthy controls with at least one live birth and no history of pregnancy loss. RSA patients exhibited significantly different frequencies of the miR-196a2CC (TT+TC vs. CC; adjusted odds ratio [AOR], 1.587; 95% confidence interval [CI], 1.042–2.417) and miR-499AG+GG genotypes (AOR, 1.671; 95% CI, 1.054–2.651) compared with the control group. The combination of miR-196a2CC and miR-499AG+GG showed synergistic effects (AOR, 3.541; 95% CI, 1.645–7.624). miR-196a2CC, miR-499AG+GG, and the miR-196a2CC/miR-499AG+GG combination are significantly associated with idiopathic RSA in Korean women. ► We investigated the association of four microRNA polymorphisms in Korean RSA patients. ► We could find the relation between four microRNA polymorphisms and occurrence of RSA. ► Four microRNA polymorphisms may contribute to incidence of RSA.