Neighbourhood deprivation and small-for-gestational-age term births in the United States

Residential context has received increased attention as a possible contributing factor to race/ethnic and socio-economic disparities in birth outcomes in the United States. Utilising vital statistics birth record data, this study examined the association between neighbourhood deprivation and the risk of a term small-for-gestational-age (SGA) birth among non-Hispanic whites and non-Hispanic blacks in eight geographical areas. An SGA birth was defined as a newborn weighing < 10th percentile of the sex- and parity-specific birthweight distribution for a given gestational week. Multi-level random intercept logistic regression models were employed and statistical tests were performed to examine whether the association between neighbourhood deprivation and SGA varied by race/ethnicity and study site. The risk of term SGA was higher among non-Hispanic blacks (range 10.8-17.5%) than non-Hispanic whites (range 5.1-9.2%) in all areas and it was higher in cities than in suburban locations. In all areas, non-Hispanic blacks lived in more deprived neighbourhoods than non-Hispanic whites. However, the adjusted associations between neighbourhood deprivation and term SGA did not vary significantly by race/ethnicity or study site. The summary fully adjusted pooled odds ratios, indicating the effect of one standard deviation increase in the deprivation score, were 1.15 [95% CI 1.08, 1.22] for non-Hispanic whites and 1.09 [95% CI 1.05, 1.14] for non-Hispanic blacks. Thus, neighbourhood deprivation was weakly associated with term SGA among both non-Hispanic whites and non-Hispanic blacks.