Antenatal multiple micronutrient supplementation (MMS) has been shown to be more effective than iron-folic acid (IFA) alone in reducing adverse pregnancy and birth outcomes. However, there is a concern that MMS containing 30 mg of iron may be less effective in reducing maternal anemia compared to IFA supplements containing 60 mg of iron. This poses a clinical and programmatic dilemma for countries with a high burden of maternal anemia (>40% prevalence) where the World Health Organization (WHO) recommends using IFA with 60 mg of iron. This study will produce causal evidence on whether MMS containing 60 or 45 mg of iron is superior to MMS containing 30 mg of iron in reducing maternal anemia and improving other important maternal and infant health outcomes. The findings of this study will inform Tanzania and similar contexts on the optimal formulation of MMS as many countries begin transitioning from IFA to MMS.
