ABSTRACT Animal and epidemiological studies show that prenatal experiences (e.g., elevated environmental pollutants, pregnancy complications, preterm birth, stress, racial discrimination) support the ‘developmental origins of health and disease’ model in relating adverse maternal experiences to compromised fetal and child development. Hypotheses suggest that the developmental window of plasticity for obesity programming initiates in utero and extends through the first two years of life, underscoring the large impact that gestational and early life exposures and corresponding targeted interventions may have on lifetime obesity risk. Current obesity interventions may be ineffective because they target children or adults past the critical age when developmental programming occurs. Because vulnerable populations are often the most impacted by exposure to environmental stressors and poor health outcomes, it is critical that research studies include them. Therefore, the overarching objective of our proposal is to increase the diversity of the ECHO Cohort. To achieve this goal, we will recruit over 500 pregnant persons and their resulting offspring into ECHO from the Medical University of South Carolina (MUSC) and implement the ECHO-wide protocol including specialized components on Physical & Chemical exposures and child Obesity outcomes. Our proposed recruitment will include 50% Black, 30% white/other and 20% Hispanic pregnant persons with half of the pregnant persons (and their conceiving partners) also contributing to the preconception cohort. The racial and ethnic diversity of the MUSC obstetrical population (i.e., 32% Black; 53% white; 12% Hispanic; and 2% Asian/Pacific Islander), and large delivery population (i.e., over 3,000 annually) will facilitate meeting our recruitment goals. In 2022, 46% of deliveries at MUSC were covered by Medicaid and 5.5% were to Spanish speaking mothers, providing further evidence of high social vulnerability in our study population. Because previous research has often been conducted in urban areas, rural communities where many Blacks reside are often understudied. Hence, as a rural state in the Deep South with poor birth outcomes and a socially vulnerable population, South Carolina’s population is historically understudied and our contribution to ECHO will have a major impact. Our aims pertaining to ECHO-wide analyses are (1) to determine the joint impact of prenatal exposure to chemical mixtures and early gestational and life exposures (i.e., hypertensive disorders of pregnancy, preterm birth) on child obesity and metabolic health; (2) to identify racial/ethnic disparities in prenatal chemical exposures and their sources (dietary choices/opportunities, use of consumer goods and personal care products, occupation, air/water) among participants in the ECHO cohort; and (3) to determine the association of mixtures of pre- conceptual and peri-conceptual chemical exposures measured in both partners with hypertensive disorders of pregnancy, preterm birth, and child obesity.

NARRATIVE An ECHO Pregnancy Cohort site in Charleston, South Carolina, will fill a critically important recruitment gap with a diverse, rural population from the Deep South. Pregnancy and preconception studies of environmental exposures that extend through childhood are critically needed to understand the link between gestational and early life exposures and their association with health and disease in children and adults. Including geographic, racial, and ethnic diversity in ECHO will strengthen the national cohort and broaden its scope.