PROJECT SUMMARY Despite recent progress, accelerated implementation of highly effective and sustainable public health policies will be required to meet the Sustainable Development Goals’ (SDG) targets for maternal and child health by 2030. The broad goal of this application is to continue to participate in all collaborative activities relevant to the mission of the Global Network (GN), which aims to develop and test potential sustainable interventions through collaborative, large-scale, high impact multi-site common research protocols. The primary objective of our research unit (RU), which represents a partnership between the University of Colorado and Guatemala, is to develop and test interventions to mitigate the priority threats to maternal-child health posed by malnutrition and infection in the context of the rapidly changing environment. The specific research expertise of our team is nutrition, infectious diseases, and biological effects of environmental stressors. This objective will be met through the following specific aims: 1) continue and enhance a strong research record and productivity as GN members; 2) continue to develop common GN protocols through high-impact clinical trials and observational studies that are transformative for maternal-child health; and 3) continue to foster a progressively stronger research partnership with our colleagues and collaborators in Guatemala and other GN sites. During the past 5-yr cycle, this RU has built a strong research record, evidenced by more than 60 GN publications (approximately 40% led by our team); by completion of longitudinal growth and neurodevelopment follow-up through 2 years in the four sites of the preconception maternal nutrition intervention trial; actively consulting on child neurodevelopmental follow-up for two other major GN trials; strengthened research capacity in Guatemala; successful implementation of all GN-initiated common protocols, including COVID-19 surveillance, with contribution of a high percentage of participant numbers and retention to each study; initiation of analyses to demonstrate adverse effects of maternal exposure to high ambient temperatures on fetal growth and birth outcomes; and securing external funding to support common protocol implementation. Major contributions to the GN by this RU include service on 2 subcommittees and co-chairing the oversight committee for the ongoing Maternal Newborn Health Registry. The positive impact of our continued participation in the GN will be accomplished by leveraging our combined expertise in nutrition, infectious diseases, and environmental stressors to design interventions to improve maternal, infant, and child health and resilience within the context of a changing environment.