Urban-suburban differences in the incidence of low birthweight in a metropolitan black population.

To study the urban-suburban differences in low birthweight among black Americans, 54,870 single births occurring to black mothers in the hospitals of Washington, DC, from 1980 to 1984 were analyzed. The observed data showed a 25% higher incidence of low birthweight (under 2501 gm) among infants born to urban mothers compared with those born to suburban mothers. Bivariate analysis showed that a greater proportion of urban mothers, compared with the proportion of suburban mothers, was teenage (23.6% vs 10.3%) and unmarried (67.6% vs 32.9%), had less than a high school education (31.7% vs 9.1%), and received inadequate prenatal care (34.3% vs 20.3%). The logit model fit to these data showed that by controlling for the above risk factors, the residential differences in the incidence of low birth rate were almost eliminated. Exploration of the medical risks associated with adverse pregnancy outcomes showed that the urban mothers had substantially higher rates for premature rupture of membrane, concurrent hypertension, pre-existing diabetes, hyperemesis, anemia, and narcotic addiction. The findings of the article underline the usefulness of studying intra-black differences rather than relying solely on race comparative research.