PROJECT SUMMARY / ABSTRACT Poor maternal cardiovascular health (CVH: behaviors + factors) in the peri-pregnancy period contributes to poor offspring CVH over the life course, especially in socially disadvantaged groups. Many interventions have targeted maternal CVH behaviors during pregnancy, but to improve offspring outcomes, targeting maternal CVH during preconception may be more effective due to critical early gestational events. However, preconception maternal CVH is understudied because half of pregnancies are unplanned, and clinical care among individuals of childbearing age is inconsistent. Pediatric clinical settings offer a novel access point for maternal preconception CVH, since >60% of births annually are to mothers who already have children. Leveraging this access to inves- tigate key timing and drivers of maternal-child CVH across the entire peri-pregnancy period (preconception, pregnancy, and postpartum) could reveal opportunities to break intergenerational cycles of cardiovascular dis- ease and related disparities. Our long-term goal is to develop strategies that optimize CVH from the beginning of life. Our objective here is to characterize key timing and drivers of maternal-child CVH across peri-pregnancy to inform future person-centered interventions. We will leverage our Young Hearts study of diverse children from clinics across Chicago to enroll and follow mothers who are likely to have another pregnancy, as well as fa- thers/co-parents and subsequent offspring, and study them from preconception through postpartum. Based on our preliminary data, we hypothesize that 1) preconception is a sensitive period for the impact of maternal CVH on offspring CVH, 2) specific social and psychological factors shape maternal capacity, opportunity, and motiva- tion for healthy lifestyle and CVH, and 3) parents and clinicians desire specific intervention strategies to optimize maternal and child CVH. We will test our hypothesis via three specific aims: 1) Compare the contributions of preconception, pregnancy, and postpartum maternal CVH to child outcomes; 2) Map the contributions of social and psychological factors to maternal CVH; and 3) Determine parents’ and clinicians’ preferences for intervention characteristics to optimize maternal-child CVH. We will analyze data from online surveys and electronic medical records among ~650 families to address Aims 1 and 2, and we will interview ~40 mothers (twice), 20 fathers/co- parents, and 30 clinicians to address Aims 2 and 3. We will then integrate quantitative and qualitative findings into a theory-based logic model for change and guiding principles for intervention. Key innovations are a novel approach to access preconception, pragmatic technology-enabled cohort design, and integration of health psy- chology theory and person-centeredness in a refined mixed-methods approach. The outcomes of this research on when to intervene, what to intervene on, and how to intervene will help direct public healt...