Prenatal experience of greater neighborhood disadvantage is associated with altered fetal volumetric brain growth in utero.

Neighborhood disadvantage is associated with worse health outcomes and rates of neurodevelopmental disorders. In childhood, experience of greater neighborhood disadvantage is associated with atypical structural and functional brain development, especially within the limbic system. Although these differences are observed throughout the lifespan, there is a profound gap in our understanding of how early neighborhood disadvantage impacts brain development. Using a prospective cohort of 199 healthy pregnancies from around Washington, DC, we performed serial fetal brain MRIs during pregnancy. Using nested linear mixed-effects models, we assess the impact of neighborhood disadvantage on brain volumes throughout fetal development. We found that greater neighborhood disadvantage was associated with significant differences in brain volumes, especially limbic areas. Increases in neighborhood disadvantage were linearly associated with larger volumes earlier in gestation and smaller volumes approaching term age. Importantly, these relationships vary depending on fetal sex, with different regions exhibiting sex-dependent vulnerabilities. These results suggest that even prior to birth, neighborhood disadvantage is associated with altered structural brain development. While the cause of this relationship is unclear, it may stem from the impact of maternal stress and adverse environmental exposures. Our findings provide an important lens to understand the impacts of how socioeconomic inequalities can influence development beginnings prenatally.