Investigation of Folic Acid Requirements in Pregnancy

Abstract

Antenatal patients have been randomly allocated to five prophylactic treatment groups at their first clinic visit. Thereafter their haemoglobin level was estimated at each visit, and they were removed from the trial if anaemia developed. In 350 consecutive patients the 2–4 day postpartum fasting serum folate level was measured. It was found that these levels were similar in the non-supplemented group 1 and the ironsupplemented group 2, but significantly raised in the iron plus 100 μg. of folic-acid-supplemented group 3. In the groups receiving iron plus 300 μg. (group 4) or 450 μg. (group 5) a day of folic acid the postpartum serum folates were further significantly raised (P<0.001). The levels in these groups are compared with those in patients not in the trial, with patients with overt megaloblastic anaemia, and with a group of nonpregnant normal adults. The median postpartum serum folate levels in groups 1, 2, and 3 were lower than in the normal non-pregnant adults, the level in group 4 receiving 300 μg. a day was identical, at 5 mμg./ml., with that of the normal adults, while the level in group 5 was supranormal. In group 4 84% of the patients had postpartum serum folate levels above 2.5 mμg./ml., and no cases of megaloblastic anaemia were found in group 4 or 5 before or after delivery. It is concluded that the minimal, oral requirements of folic acid in late pregnancy are close to 300 μg. a day. © 1966, British Medical Journal Publishing Group. All rights reserved.