Racial residential segregation and low birth weight in Michigan's metropolitan areas.

OBJECTIVES

We examined the influence of racial residential segregation, independent of neighborhood economic factors, on the overall and specific etiological risks of low birth weight.

METHODS

We geocoded all singleton births in Michigan metropolitan areas during 2000 to census tracts. We used hierarchical generalized linear models to investigate the association between low birth weight (< 2500 g) and neighborhood-level economic and racial segregation, controlling for individual and neighborhood characteristics. We analyzed competing risks of the 2 etiologies of low birth weight: intrauterine growth restriction and preterm birth.

RESULTS

Living in a Black segregated area was associated with increased odds (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 1.03, 1.29; P < .05) of low birth weight after adjusting for individual- and tract-level measures. The analysis suggested that the association between low birth weight and racial segregation was attributable primarily to increased risk of intrauterine growth restriction (OR = 1.19; 95% CI = 1.03, 1.37; P < .05).

CONCLUSIONS

Odds of low birth weight are higher in racially segregated Black neighborhoods in Michigan's metropolitan areas, independent of economic factors. The association appears to operate through intrauterine growth restriction rather than preterm birth.