Background: Multiple micronutrient supplements could increase hemoglobin and improve micronutrient status of pregnant women more than iron supplements alone or iron with folic acid.
Objective: To compare the effects of multiple micronutrients with those of iron supplements alone or iron with folic acid, on hemoglobin and micronutrient status of pregnant women.
Methods: Studies were identified in which pregnant women were randomized to treatment with multiple micronutrients, or with iron with or without folic acid. A pooled analysis was conducted to compare the effects of these supplements on maternal hemoglobin, anemia, and micronutrient status. Effect size was calculated for individual and combined studies, based on mean change from baseline to final measure in the group receiving iron, with or without folic acid, minus the mean change in the group, divided by the pooled standard deviation of the two groups. The effect on the relative risk of anemia or iron deficiency was calculated as the probability of anemia or iron deficiency in the group receiving multiple micronutrients divided by the probability in the group receiving iron, with or without folic acid.
Results: Multiple micronutrient supplements had the same impact on hemoglobin and iron status indicators as iron with or without folic acid. There was no overall effect on serum retinol or zinc. In the only study in which status of other micronutrients was analyzed, a high prevalence of multiple deficiencies persisted in the group receiving multiple micronutrients provided with daily recommended intakes of each nutrient.
Conclusions: Multiple micronutrient supplements increased hemoglobin synthesis to the same extent as supplementation with iron with or without folic acid, although often they contained lower amounts of iron. The amount of supplemental iron and other nutrients that can enable pregnant women with micronutrient deficiencies to achieve adequate status remains to be determined.