Roles of methylenetetrahydrofolate reductase C677T polymorphism in repeated pregnancy loss

Congenital thrombophilia in repeated pregnancy lost (RPL) has been noted for years. Methylenetetrahydrofolate reductase (MTHFR) gene is an interesting gene, mentioned for its possible roles in RPL. There is considerable controversy regarding the clinical role of MTHFR C677T polymorphism as a risk factor of RPL. Here, a summative analysis is performed on the recent previous reports on the MTHFR C677T and its correlation to RPL. The metanalysis was performed to assess the correlation between the pattern of MTHFR C677T polymorphism and RPL. From available eight case-control studies, 752 patients and 625 controls are evaluated. The overall frequencies of 4G allele for the patients and controls are 31.5 and 33.5, respectively. According to this study, 53.1% of subjects with T allele have RLP while 55.3% of subjects without T allele have RLP. From overall risk estimation, the subjects with T alleles have 0.96 times lower risk to RLP. According to this analysis, the pattern of MTHFR C677T polymorphism might not represent a useful marker of increased risk for RPL. In addition, there was no association between pattern of MTHFR C677T polymorphism and ethnicity of the patients in this study.