Impact of maternal methylenetetrahydrofolate reductase C677T polymorphism on intervillous and decidual pathology with pregnancy loss

Aim The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and intervillous and decidual pathology in patients with pregnancy loss was investigated. Methods We performed a cross-sectional study on 243 patients presenting with pregnancy loss for the degree of intervillous fibrin and thrombosis (IT), and decidual fibrin and thrombosis (DT) and determined their MTHFR C677T genotypes. Overall differences in age, body mass index (BMI), gravidity, parity, number of pregnancy losses and gestational period when the pathologic samples were obtained, also were determined. Results There were no significant differences in age, BMI, gravidity, parity, number of pregnancy losses and gestational period, relative to MTHFR C677T genotype (TT vs CT vs CC). There were significantly more T allele carriers and TT genotype patients among patients with severe IT (odds ratio [OR] 1.653, P = 0.033 and OR 2.246, P = 0.032, respectively) and those with severe IT and decidual thrombosis (OR 2.602, P = 0.012 and OR 3.375, P = 0.035, respectively). The CC genotype was protective against the four studied pathologic grades. Conclusion To our knowledge, this is the first study showing that the MTHFR C677T TT genotype and T allele are associated with severe intervillous and decidual pathologies in patients with pregnancy loss. Differences in pathologic grades of MTHFR C677T TT genotype could support the hypothesis that further periconceptional treatment for pregnancy loss could be customized depending on single nucleotide polymorphisms.