Maternal anemia modifies the effect of multiple micronutrient supplements on birth weight and infant mortality in Indonesia

Objective To assess effects of maternal anemia on the impact of maternal multiple micronutrient (MMN) supplementation compared to iron & folic acid (IFA) in a double blind RCT in Indonesia ( ISRCTN34151616 ). Methods We analyzed 14611 singleton births with data on maternal hemoglobin (Hb), height, parity, education, gestational age at birth, sex, season of birth & household wealth. Mortality was analyzed with Cox proportional hazards models; birth weight (BW) & maternal Hb with linear models; low birth weight (LBW), small for gestational age (SGA) & preterm‐LBW with logistic models. Results In anemic women MMN reduced early infant mortality (< 90 days of birth) by 39% [Adj HR 0.61; 95%CI 0.49–0.78 p<0.001; interaction (int) p=0.04] and neonatal mortality by 36% (Adj HR 0.64; CI=0.47–0.86 p=0.003; int p=0.18). MMN improved BW by 37g (CI −1 to 74 p=0.056; int p=0.01), and reduced LBW by 17% (aRR 0.83; CI 0.66–1.05 p=0.11; int p=0.04) and preterm‐LBW by 40% (aRR 0.60; CI 0.42–0.87 p=0.007; int p=0.002), and improved Hb by 0.28g/dl (CI −0.031 to 0.59 p=0.08) in anemic women. Conclusions Maternal MMN supplements, as compared to IFA, have greater benefits on infant survival and birth weight in anemic than in non‐anemic women. Funding: Turner Foundation, UNICEF, CHHD, USAID Indonesia grant # 497G00010000100. AusAID supported SKS's PhD at U of Sydney.