PROJECT SUMMARY This proposal serves to leverage the Safe Passage Study ECHO (PASS ECHO) research infrastructure that has recruited a large cohort of ECHO mother/child pairs (n=6.647) for continued follow-up, as well as continued enrollment of new pregnancies and initiating a preconception cohort. The success of the PASS ECHO research team from 2016-2023, both in scientific collaboration and completing of operational tasks, provides an excellent foundation for increased enrollment and retention of ECHO participants, including a large proportion of rural and American Indian participants. PASS ECHO has a specialization in the ECHO Obesity health outcome. The following specific aims relate directly to advancing collaborative ECHO Cohort science and completing operational tasks relevant for successful participation in the next phase of ECHO. (SA1) Examine the effects of prenatal allostatic load, and its biomarkers, on childhood obesity and neurodevelopment. (SA2) Examine the independent and joint effects of prenatal life-style related exposures on child obesity-related outcomes, and how nutrition may impact these relationships. (SA3) Build upon demonstrated successful strategies and strong community/participant relationships to implement the ECHO-wide protocol v3.0 with deliberate efforts to increase participation in American Indian and rural communities.