Maternal Use of Vitamins and Infant Congenital Malformation

Abstract

It is a generally held belief that maternal use of folic acid can drastically reduce the risk of a neural tube defect in the offspring. The data presented here do not support this idea: women who reported the use of folic acid in early pregnancy (most of them starting before the last menstrual period) did not have a lower rate of neural tube defect infants than expected. In contrast to this, there was a nearly significantly low rate of such defects after maternal use of multivitamins. The explanation to this is unclear. No beneficial effect on malformation rate was seen from use of vitamin B12 and other B, C, or D vitamins. Two specific vitamins have been associated with a teratogenic effect: high doses of vitamin A and use of vitamin E. Only few women had used high doses of vitamin A and the literature on the subject reports different results. Such treatment during pregnancy should be avoided. An association between use of vitamin E and congenital malformations in the offspring is probably due to confounding by indication: subfertility and repeated previous miscarriages.