Effect of multivitamin and vitamin A supplements on weight gain during pregnancy among HIV-1-infected women.

BACKGROUND The pattern of weight gain during pregnancy among HIV-infected women is largely unknown. Multivitamin supplementation was shown to be effective in preventing adverse pregnancy outcomes among HIV-positive women. These protective effects could be mediated in part by an improvement in the pattern of gestational weight gain. OBJECTIVE We examined the effects of multivitamin and vitamin A supplements on weight gain during the second and third trimesters of pregnancy among HIV-infected women. DESIGN We enrolled 1075 pregnant, HIV-1-positive women from Dar es Salaam, Tanzania, in a randomized, placebo-controlled trial. Using a 2-by-2 factorial design, we assigned each woman to 1 of 4 regimens: multivitamins (thiamine, riboflavin, niacin, folic acid, and vitamins B-6, B-12, C, and E), vitamin A, multivitamins including vitamin A, or placebo. The women took these oral supplements daily and were weighed monthly until the end of pregnancy. RESULTS The mean rate of weight gain was 306 g/wk during the second trimester and 247 g/wk during the third trimester. During the third trimester, average weight gain was significantly greater (by 304 g; 95% CI: 17, 590; P = 0.04) and the risk of low rate of weight gain (<or= 100 g/wk) was significantly lower (relative risk: 0.73; 95% CI: 0.58, 0.93) in women who received multivitamins than in women who did not. Multivitamins including vitamin A were protective against low weight gain during the second trimester compared with multivitamins alone. CONCLUSION Multivitamin supplementation during pregnancy improves the pattern of weight gain among HIV-infected women.