Effect of multiple micronutrient versus iron-folate supplementation during pregnancy on intrauterine growth

This review examines the effects of prenatal multiple micronutrient (MM) supplementation (≥5 micronutrients) on intrauterine growth. We identified publications from 16 randomized controlled trials through PubMed and EMBASE database searches. Meta-analyses were performed by pooling results, and sub-analyses by timing of intervention and amount of iron were also done. The primary outcome measures were birthweight, low birthweight (LBW; <2,500 g) and small for gestational age (SGA). Prenatal MM supplementation significantly reduced the incidence of LBW (risk ratio, RR: 0.86; 95% CI: 0.81-0.92) and SGA (RR: 0.83; 95% CI: 0.73-0.95) compared to iron-folate supplementation; mean birthweight was significantly higher by 55 g for MM with borderline increases in gestational age. MM supplementation was associated with larger decreases in the risk of LBW and SGA in the subgroup of trials that used supplements containing 60 mg of iron, but were not statistically significantly different from those for trials that used 30 mg iron. Prenatal MM supplementation improved intrauterine growth and can be recommended instead of prenatal IFA supplements in settings where micronutrient deficiencies are common.