Folic acid, Vitamin B 12, and homocysteine in smoking and non-smoking pregnant women

Abstract

Introduction: Lower plasma levels of vitamins may result in hyperhomocysteinemia, a known risk factor in pregnancy. As smoking may alter nutrition, we were interested in its effect on folate and Vitamin B 12 in pregnancy. Materials and methods: A cross-sectional study of 62 smoking and 76 non-smoking healthy pregnant women. Serum folic acid, Vitamin B 12 and homocysteine were measured at four points in pregnancy: 0–10, 11–20, 21–30 and 31–40 weeks. Results: Folate concentrations of the smoking women decreased continuously during pregnancy, and were significantly lower than those of non-smoking women during the last 30 weeks. Vitamin B 12 levels decreased significantly in both groups. The homocysteine levels were higher in the smoking group during the second-half of pregnancy. Discussion: Smoking women have lower and decreasing folate levels during pregnancy, possibly as a result of lower intake of these nutrients. Lower folate levels can lead to hyperhomocysteinemia, a known risk factor for several complications in pregnancy. This is an other important reason to convince pregnant women to refrain from smoking.