Effect of multiple micronutrient supplementation on pregnancy and infant outcomes: a systematic review
Supplementation with multiple micronutrients (MM) during pregnancy may result in improved pregnancy and infant outcomes. The study conducted meta-analyses of randomised controlled trials that evaluated the effects of prenatal supplementation with MM (defined as containing at least five micronutrients and typically included iron or iron and folic acid). The outcomes of interest are low birth weight (<2500 g), birth weight, small-for-gestational age (SGA), gestational age, preterm birth (<37 weeks' gestation), stillbirth and neonatal death, maternal morbidity and mortality. The study identified eligible studies through PubMed and EMBASE database searches. Meta-analyses were performed by pooling results for outcomes that were reported from more than one trial and sub-analyses were conducted to evaluate the effect of timing of intervention and amount of iron. The study includes published results from 16 trials in this review. Compared with control supplementation that was usually iron plus folic acid in most studies, MM supplementation results in a significant reduction in the incidence of low birth weight [pooled risk ratio (RR) 0.86; 95% confidence interval (CI) 0.81, 0.91] and SGA (pooled RR 0.83 [95% CI 0.73, 0.95]) and an increase in mean birth weight (weighted mean difference (WMD) 52.6 g [95% CI 43.2 g, 62.0 g]). There is no significant difference in the overall risk of preterm birth, stillbirth, and maternal or neonatal mortality, but the study finds an increased risk of neonatal death for the MM group compared with iron-folate in the subgroup of five trials that began the intervention after the first trimester (RR 1.38 [95% CI 1.05, 1.81]). None of the studies evaluated maternal morbidity. Compared with iron plus folic acid supplementation alone, prenatal maternal supplementation with MM results in a reduction in the incidence of low birth weight and SGA, but increased risk of neonatal death in the subgroup of studies that began the intervention after the first trimester.
[Adapted from author]