The science of maternal nutrition and its application programmatically continues to evolve as societies change and demographics shift. Yet, across the globe, in many diverse settings, questions remain about maternal weight gain and diet. How much weight should a woman gain during pregnancy? How does ideal weight gain vary according to pre-pregnancy weight and other lifestyle factors? How do we effectively monitor weight gain and design and implement interventions to ensure appropriate gain?

This brief by Gilberto Kac, Thais Carrilho, Kathleen Rasmussen, and Joy Del Rosso summarizes our understanding of weight gain during pregnancy and the consequences of gaining too little or too much. It shares data on the prevalence of inadequate and excessive weight gain in low- and middle-income countries (LMICs) and highlights the need to prioritize the issue of inadequate weight gain. It also presents what we know about weight gain monitoring and counseling interventions and the impact of maternal balanced energy and protein (BEP) supplementation on weight gain. Finally, it offers recommendations for strengthening pregnancy weight gain interventions and suggests a way forward for future research.