Effects of Prenatal and Postnatal Maternal Multiple Micronutrient Supplementation on Child Growth and Morbidity in Tanzania: A Double-Blind, Randomized Controlled Trial

Objectives Maternal micronutrient status is critical for child growth and nutrition. It is unclear whether maternal multiple micronutrient supplementation (MMS) during pregnancy and lactation improves child growth and prevents child morbidity. The aim of this study was to determine the effects of prenatal and postnatal maternal MMS on child growth and morbidity in Tanzania. Methods In this double-blind, randomized controlled trial, 8,379 HIV-negative pregnant women were enrolled from Dar es Salaam, Tanzania, between 2001 and 2004. From pregnancy (12 to 27 weeks of gestation) through 6 weeks postpartum, participants were randomized to receive daily oral MMS or placebo. All women received daily iron and folic acid during pregnancy. From 6 weeks postpartum through 18 months postpartum, 3,100 women were re-randomized to MMS or placebo. Child growth measures, hemoglobin concentrations, and infectious morbidities were assessed longitudinally from birth to up to 18 months. Linear mixed-effects models were used to estimate the effects of prenatal and postnatal MMS on child growth z-scores and hemoglobin concentrations. Cox proportional hazards models were used to estimate the effects on undernutrition. Generalized estimating equations were used to estimate the effects on anemia and infectious morbidities. Results Prenatal MMS led to modest increases in weight-for-age z-score (mean difference: 0.050; 95% CI: 0.002, 0.099; p = 0.04) and length-for-age z-score (mean difference: 0.062; 95% CI: 0.013, 0.111; p = 0.01) during the first six months of life but not thereafter. Prenatal MMS did not have significant benefits for anemia, morbidity, or other child growth outcomes. Postnatal MMS did not have significant benefits for any child outcomes. Conclusions While maternal MMS is a proven strategy to prevent adverse birth outcomes, other approaches may also need to be considered to curb the high burdens of child morbidity and growth faltering. Funding Sources This work was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health.