Vitamins and Perinatal Outcomes among HIV-Negative Women in Tanzania
What this study found
Prenatal multivitamin supplementation improved fetal growth outcomes but did not meaningfully reduce prematurity or fetal death. Mean birth weight was 3148 g versus 3083 g, a 67 g increase (P<0.001), and low birth weight <2500 g was reduced from 9.4% to 7.8% (RR 0.82, 0.70 to 0.95; P=0.01). Small-for-gestational-age births were also lower at 10.7% versus 13.6% (RR 0.77, 0.68 to 0.87; P<0.001). Preterm birth <37 weeks was unchanged (16.9% vs 16.7%; RR 1.01, 0.91 to 1.11; P=0.87) and fetal death was not significantly different (4.3% vs 5.0%; RR 0.87, 0.72 to 1.05; P=0.15). Maternal anemia…
- Study & population
- Randomized, placebo-controlled trial among HIV-negative pregnant women attending antenatal clinics in Dar es Salaam, Tanzania.
- Intervention
- Daily oral prenatal multivitamin supplementation, taken once daily from enrollment until 6 weeks after delivery, in addition to standard prenatal iron (60 mg elemental iron daily) and folic acid (0.25 mg daily).
- Key limitation
- The multivitamin was added on top of routine iron and folic acid, so the specific contribution of the multivitamin components is not fully isolated.
View source
Open PDFOriginal abstract
Methods In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or placebo. All the women received prenatal supplemental iron and folic acid. The primary outcomes were low birth weight (<2500 g), prematurity, and fetal death. Results The incidence of low birth weight was 7.8% among the infants in the multivitamin group and 9.4% among those in the placebo group (relative risk, 0.82; 95% confidence interval [CI], 0.70 to 0.95; P = 0.01). The mean difference in birth weight between the groups was modest (67 g, P<0.001). The rates of prematurity were 16.9% in the multivitamin group and 16.7% in the placebo group (relative risk, 1.01; 95% CI, 0.91 to 1.11; P = 0.87), and the rates of fetal death were 4.3% and 5.0%, respectively (relative risk, 0.87; 95% CI, 0.72 to 1.05; P = 0.15). Supplementation reduced both the risk of a birth size that was small for gestational age (<10th percentile; 10.7% in the multivitamin group vs. 13.6% in the placebo group; relative risk, 0.77; 95% CI, 0.68 to 0.87; P<0.001) and the risk of maternal anemia (hemoglobin level, <11 g per deciliter; relative risk, 0.88; 95% CI, 0.80 to 0.97; P = 0.01), although the difference in the mean hemoglobin levels between the groups was small (0.2 g per deciliter, P<0.001). Conclusions Multivitamin supplementation reduced the incidence of low birth weight and smallfor-gestational-age births but had no significant effects on prematurity or fetal death. Multivitamins should be considered for all pregnant women in developing countries. (ClinicalTrials.gov number, NCT00197548.)