Quinn MK, Smith ER, Williams PL, et al. - Given the benefit of maternal micronutrient supplementation in pregnancy (MMS) on improving birth weight among infants in low- and middle-income countries, and recent evidence indicating greater survival benefits of MMS for female infants vs male infants, researchers studied the potential mechanisms of action of MMS on infant mortality among Tanzanian infants, by analyzing data from pregnant women and newborns who were examined in a randomized, double-blind, placebo-controlled trial in Tanzania, investigating mediators of the influence of MMS on 6-wk infant mortality. They found that differences in mechanisms associated with birth outcomes may account for the potential gender-specific influences of MMS on mortality. For female infants, increased gestation duration and improved intrauterine growth were the two factors that completely mediated the observed impact of MMS on 6-wk mortality, while no major contribution of these mechanisms was observed among male infants, in the context of the Tanzanian trial.