A Pilot Study on Multigenic Thrombophilic Risk in Recurrent Pregnancy Loss: Interactions Between MTHFR Polymorphisms and Classical Thrombophilia-Associated SNPs

Recurrent spontaneous miscarriages represent a significant reproductive challenge, often associated with inherited thrombophilia. Among the genetic factors involved, methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms have been increasingly studied. The two main variants, MTHFR C677T and MTHFR A1298C, have been suggested to contribute to thrombotic events and adverse pregnancy outcomes. This study aims to evaluate the higher prevalence and potential role of MTHFR gene polymorphisms (C677T and A1298C) in the etiology of recurrent spontaneous miscarriages in pregnant women with inherited thrombophilia, in comparison with the classical thrombophilia-associated SNPs—F5 Leiden and the F2 G20210A gene mutation. In this single-center retrospective observational study, 64 women with recurrent pregnancy loss and confirmed inherited thrombophilia were evaluated. Genomic DNA extracted from peripheral blood samples was analyzed for thrombophilia-associated polymorphisms, including F5 Leiden (G1691A), F2 G20210A, MTHFR C677T, MTHFR A1298C, SERPINE1 4G/5G, and F13A1 V34L, using a real-time PCR-based Bosphore® Thrombophilia Panel. The presence of MTHFR C677T and A1298C polymorphisms was investigated and compared to the incidence of F5 Leiden and F2 G20210A gene SNPs. Associations between genotypes and clinical characteristics, including the number of pregnancy losses, were assessed using chi-square tests, Kruskal–Wallis analysis, and logistic regression models. The most frequently detected polymorphisms were heterozygous variants of the MTHFR gene, with prevalences of 57.8% for C677T and 53.1% for A1298C. Homozygous MTHFR C677T was significantly associated with a higher number of pregnancy losses (Kruskal–Wallis test, p = 0.001). Similarly, the homozygous MTHFR A1298C genotype showed a significant association with increased miscarriage frequency (p = 0.012). Classical thrombophilic mutations were less frequent, with F2 G20210A identified in only two patients, although its presence was associated with a higher number of pregnancy losses (p = 0.030). These findings suggest that combined thrombophilic polymorphisms may contribute to recurrent pregnancy loss, although larger studies are required to confirm these observations.