Maternal nutrition interventions to improve maternal, newborn, and child health outcomes.

Maternal undernutrition affects a large proportion of women in many developing countries, but has received little attention as an important determinant of poor maternal, newborn, and child health (MNCH) outcomes such as intrauterine growth restriction, preterm birth (PTB), and maternal and infant morbidity and mortality. We recently evaluated the scientific evidence on the effects of maternal nutrition interventions on MNCH outcomes as part of a project funded by the Gates Foundation to identify critical knowledge gaps and priority research needs. A standardized tool was used for study data abstraction, and the effect of nutrition interventions during pregnancy or of factors such as interpregnancy interval on MNCH outcomes was assessed by meta-analysis, when possible. Several nutrient interventions provided during pregnancy have beneficial effects on MNCH outcomes, but are not widely adopted. For example, prenatal calcium supplementation decreases the risk of PTB and increases birthweight; prenatal zinc, omega-3 fatty acids and multiple micronutrient supplements reduce the risk of PTB (<37 weeks), early PTB (<34 weeks) and low birthweight (LBW), respectively. Among currently implemented interventions, balanced protein-energy and iron-folic acid supplementation during pregnancy significantly reduce the risk of LBW by 20-30% in controlled settings, but variable programmatic experiences have led to questionable effectiveness. Early age at pregnancy and short interpregnancy intervals were also associated with increased risk of PTB, LBW and neonatal death, but major gaps remain on the role of women's nutrition before and during early pregnancy and nutrition education and counseling. These findings emphasize the need to examine the benefits of improving maternal nutrition before and during pregnancy both in research and program delivery.