When ≥7.0 ng/mL of the serum folate level is defined to minimize the risk of the incidence of NTDs based on a previous report [12], 26.3% (54/205) of infertile women require folic acid supplementation, including 12.5% (9/72 women), 30.0% (30/100 women) and 45.5% (15/33 women) of women with MTHFR 677CC, CT and TT, respectively. Here, MTHFR is linked to Infertility.