Objectives: To examine the influence of racial residential segregation independent of neighborhood economic factors on the overall and specific etiologic risks of low birth weight births.

Methods: All singleton births in Michigan metropolitan areas from the year 2000 were geocoded to Census tracts. We used hierarchical generalized linear models to investigate the association between low birth weight (<2500g) and neighborhood-level economic and racial segregation controlling for mother’s race and age.

Results: Living in a black segregated area was associated with increased odds (OR=1.15) of low birth weight after controlling for the impact of other individual or and tract-level measures. Comparing the two etiologies that drive low birth weight births – intrauterine growth restriction and preterm birth – suggests that the association with racial segregation was due primarily to intrauterine growth restriction (OR=1.19).

Conclusions: Odds of low birth weight births are higher in racially segregated African American neighborhoods in metropolitan areas independent of economic factors. The association appears to operate through intrauterine growth restriction rather than preterm birth.