Contribution of Maternal Adherence to the Effect of Multiple Micronutrient Supplementation During Pregnancy: A Systematic Review and Individual Participant Data Meta-analysis

Multiple micronutrient supplements (MMS) in pregnancy reduces risk of infant low birth weight (LBW) and improves other maternal and infant outcomes compared with iron and folic acid (IFA) supplements alone. However, the impact of timing of initiation and adherence on the MMS effectiveness in real-world programs remains unclear. To address this, we conducted a 2-stage individual participant data meta-analysis that included 15 randomized trials (61,204 pregnant women) and assessed whether the relative effect of MMS differed by the following: adherence alone; adherence in combination with gestational age at initiation; and the total number of tablets taken. We also evaluated the observational association of these factors with outcomes among participants who received MMS.