Project Summary/Abstract The foundation for cardiovascular health (CVH) is laid in early life by intergenerational interactions, passed from parent to child, that have long-lasting biological and behavioral consequences. Lifestyle interventions can promote CVH among mothers and their children over time. Academic partnerships with home visiting organizations that reach families experiencing health disparities advance intergenerational CVH equity. This study builds on a decades-long academic-home visiting partnership between the research team at Washington University in St. Louis and Parents as Teachers (PAT), an evidence-based home visiting program located in all 50 states. Most recently, our partnered work demonstrated the effectiveness of Healthy Eating and Active Living Taught at Home (HEALTH), in which we successfully tested a lifestyle intervention to promote ideal weight and CVH among pregnant and young mothers and their children. We now seek to advance this work with the ENRICH Collaborative by rigorously testing the ongoing CVH impact of this implementation-ready approach. During the UG3 planning phase (years 1-2), we will work with the ENRICH Collaborative to identify a common CVH protocol informed by HEALTH. In the UH3 implementation phase (years 3-7), we will rigorously test the ongoing impact on CVH of this implementation-ready approach for mothers and young children, delivered over 3 years, beginning prenatally and continuing to 30 months post- childbirth. The Hybrid Type 1 cluster-randomized pragmatic trial builds on this partnership (N=10 sites in high burden St. Louis, Missouri, metro region; 750 mother-child dyads; study population with one or more of the following characteristics associated with increased risk of cardiovascular disease: Black or Latinx, body mass index ≥ 30, and/or socioeconomic disadvantage). We will determine the effect of HEALTH on maternal CVH as assessed by a composite score on the American Heart Association Life’s Simple 7 over 3 years from enrollment (before 20 weeks pregnancy) to follow-up at birth, 6, 18, and 30-months post childbirth; and on child CVH assessed by BMIz trajectory and diet, activity, sleep, and parental influence from birth to 6, 18, and 30-month follow-up. We will apply expertise in implementation science to ensure the intervention has equitable implementation and impact across PAT and the ENRICH Collaborative. This significant study will further advance scientific understanding and evidence-based practice on how to disrupt the impact of cardiovascular risk that passes across generations to improve CVH equity. The innovation of this study is that it will rigorously determine the impact of HEALTH on the transfer of lifestyle behaviors from mother to child, across the childbearing continuum.