Measuring the Effect of Neighborhood Racial Segregation on Fetal Growth

Prior studies of neighborhood racial segregation and intrauterine growth have not accounted for confounding factors in early life. We used the Life-Course Influences on Fetal Environment Study of births to Black women in metropolitan Detroit, 2009–2011, (N = 1,408) to examine whether health and social conditions in childhood and adulthood confound or modify the association of neighborhood segregation (addresses during pregnancy geocoded to census tract racial composition) and gestational age-adjusted birthweight. Before adjusting for covariates, women living in a predominantly (≥75%) Black neighborhood gave birth to 47.3 grams (95% CI: –99.0, 4.4) lighter infants, on average, compared with women living in <75% Black neighborhoods. This association was confounded by adulthood (age at delivery, parity, neighborhood deprivation) and childhood (parental education, neighborhood racial composition) factors and modified by adulthood socioeconomic position. These findings underscore the complex relationship between neighborhood racial segregation and birth outcomes, which would be enhanced through a life course framework.