The 677 C-T Methylenetetrahydrofolate Reductase Mutation Does Not Predict Increased Maternal Homocysteine During Pregnancy

Abstract

In Brief OBJECTIVE To test the hypothesis that, regardless of the presence of the 677 C-T methylenetetrahydrofolate reductase (MTHFR) mutation, maternal homocysteine concentrations will not be significantly different in women who are taking prenatal vitamins containing folic acid, and to test this relationship in preeclampsia because homocysteine concentrations are higher in preeclamptic pregnancies. METHODS Fifty-seven pregnant white women (control and preeclamptic) with and without the 677 C-T MTHFR mutation were studied. Total plasma homocysteine and plasma folic acid were analyzed. RESULTS Homocysteine concentrations were not different by MTHFR genotype (wild type 677 CC 8.7 ± 5.6 μM versus mutant 677 TT 9.0 ±5.7 μM, P = .84) in preeclamptic or normal pregnancies. However, mean homocysteine concentrations were significantly increased in preeclamptic pregnancies compared with those in normal pregnancies (10.6 ± 7.3 μM versus 7.2 ± 3.0 μM, P < .03) as previously reported. CONCLUSION The 677 C-T MTHFR polymorphism does not significantly affect maternal homocysteine concentrations in most women taking prenatal vitamins including women with preeclampsia. The increase in plasma folic acid likely affects maternal homocysteine more than the MTHFR genotype. If homocysteine is considered a thrombophilia risk factor, the concentration of the amino acid and not a particular genotype should be determined. The 677 C-T methylenetetrahydrofolate reductase gene variant does not predict increased maternal homocysteine during pregnancy, and this is likely the result of increased folic acid intake.