Zinc supplementation during pregnancy and effects on growth and morbidity in low birthweight infants: a randomised placebo controlled trial

Background infant malnutrition and mortality rates are high in less-develop ed countries especially in low-birthweight infants. Zinc deficiency is also widely prevalent in these circumstances. We aimed to assess the effect of daily zinc supplements given to pregnant mothers on their infants' growth a nd morbidity. Methods We did a double-blind, placebo controlled. randomised trial in 199 and 221 Bangladeshi infants whose mothers took 30 mg daily elemental zinc o r placebo, respectively, from 12 to 16 weeks' gestation until delivery. Inf ants were followed up until 6 months of age. We obtained data for morbidity every week by mothers' recall. Infants' anthropometric measurements were d one every month, and their serum zinc was assessed at 1 and 6 months of age . Findings Infants of mothers who received zinc during pregnancy had at age 6 months reduced risks compared with those in the placebo group for acute di arrhoea (risk ratio 0.84; 95% CI 0.72-0.98), dysentery (0.36; 0.25-0.84). a nd impetigo (0.53; 0.34-0.82). These reductions were seen in low-birthweigh t infants but not in those with normal birthweight. There were no differenc es in infant growth or serum zinc concentrations between treatment groups. Interpretation Maternal zinc supplementation during pregnancy resulted in a reduction of the health risks in Bangladeshi low-birthweight infants. alth ough this intervention did not improve birthweight. Whether zinc should be added to usual antenatal supplements in regions with high rates of low birt hweight should be reviewed.