PLASMA HOMOCYST(E)INE CONCENTRATIONS IN PREGNANT AND NONPREGNANT WOMEN WITH CONTROLLED FOLATE INTAKE

Objective: To assess the effects of folate intake and pregnancy on pla sma total homocyst(e)ine concentrations in women during the second tri mester of pregnancy compared with young, healthy nonpregnant women. Me thods: The diet provided either 450 or 850 mu g of folate per day. The se levels are approximately the current (400 mu g/day) and previous (8 00 mu g/day) Recommended Dietary Allowances for folate in pregnant wom en. Folate was provided as both food folate (120 mu g/day) and supplem ental folic acid (either 330 or 730 mu g/day) for a period of 12 weeks . Plasma homocyst(e)ine (sum of free and protein-bound homocysteine), serum folate, and erythrocyte folate concentrations were determined we ekly. Results: Homocyst(e)ine concentrations were lower in pregnant wo men during the second trimester of normal pregnancy than in nonpregnan t controls, independent of dietary folate intake. The overall mean (+/ - standard deviation) homocyst(e)ine concentration of the pregnant sub jects (5.4 +/- 1.4 mu mol/L) was significantly lower than that observe d in the nonpregnant control group (8.7 +/- 1.7 mu mol/L) (P < .0001). This difference in homocyst(e)ine concentrations remained constant th roughout the 12 weeks of the investigation. Conclusion: The folate int akes in this investigation were adequate to maintain constant homocyst (e)ine concentrations in pregnant and nonpregnant women. The lower hom ocyst(e)ine concentrations observed in pregnant subjects compared with nonpregnant controls may be a physiologic response to pregnancy. (Obs tet Gynecol 1998;92:167-70. (C) 1998 by The American College of Obstet ricians and Gynecologists.)