PROJECT SUMMARY Adverse birth outcomes, such as preterm birth, low birth weight, and small for gestational age, have serious health consequences not just during infancy but across the life course. Past research shows an immigrant advantage in birth outcomes compared to women born in the United States; however, recent studies increasingly show that immigrant women have worse birth outcomes than non-Hispanic white women. Much research at the intersection of migration and reproductive, maternal, and child health has focused on individual exposures and risk factors. Yet there is growing evidence that structural factors such as migration policies are associated with health disparities, and there is limited understanding of the process by which social and policy environments impact individual-level maternal–fetal medicine outcomes. This K01 Mentored Research Scientist Development Award focuses on conceptualizing this structural context and its potential impact on women’s pregnancy and birth outcomes through pathways of structural stigma, social disadvantage, and spatial isolation. Three proposed areas of training will allow the candidate to develop an independent research career focused on migration and structural determinants of perinatal health: 1) perinatal epidemiology and demography, 2) spatial and data science techniques, and 3) qualitative methods. The specific aims will be achieved using National Center for Health Statistics period-linked infant birth–death data, the National Survey of Family Growth, and qualitative data on immigrant experiences of social and policy environments collected during the project period. These data will be used to carry out the following aims: 1) to examine multilevel effects of social and policy environments on foreign and US-born women’s pregnancy and birth outcomes, 2) to investigate area-level measures of social and policy environments and foreign and US-born women’s pregnancy and birth outcomes, and 3) to explore immigrant women’s experiences of stress due to social and policy environments at destination and their implications for birth outcomes. Expected outcomes are rigorous knowledge of the impact of structural contexts on pregnancy and birth outcomes as well as health system precursors of birth outcomes for immigrants in the US. Findings from this research can both identify immigrant responses to social and policy environments and suggest educational and behavioral interventions that could improve immigrant responses to structural environment stressors, access to prenatal care, and birth outcomes. Training and insights from this project will lead to development of a large-scale R01 study extending this line of research and will further help develop policies that promote maternal, perinatal, and child health.