Statistic analysis revealed that MTHFR C677T polymorphismsare associated with recurrent pregnancy loss (for CT vs CC: OR= 3.37, 95% CI: 1.44 - 7.87, p = 0.0049; for (677CT + 677TT) vs CC: OR= 3.25, 95% CI: 1.46 - 7.26, p = 0.004; for T vs C: OR= 2.74, 95% CI: 1.55 - 5.55, p = 0.005).