Differences in infant mortality by race, nativity status, and other maternal characteristics

The objective of this study was to examine the effects of nativity status (native vs foreign born) and other maternal characteristics (age, parity, education, and marital status) on infant, neonatal, and postneonatal mortality among white and black mothers. The design of this nonrandomized cohort study was based on birth and death certificates. The setting involved live births among US residents (excluding California, Texas, and Washington) in 1983 and 1984. The participants included white mothers with 4.4 million births and black mothers with 926,000 births in single deliveries. There were no interventions. With regard to measurements (the main results), after adjusting for other risk factors, neonatal mortality risk was 22% lower among the black foreign-born mothers than among the black native-born mothers, while among white infants, there was no risk difference by nativity. Relative risks were more similar for postneonatal mortality, ie, 24% lower among black foreign-born mothers and 20% lower among white foreign-born mothers. Combining the several categories of risk factors into three broad maternal risk groups, there was a near-doubling of black and near-tripling of white infant mortality rates between the low and high levels of maternal risk. We concluded that if the infant mortality rate in the low-risk groups could be achieved by the moderate- and high-risk groups, there would be a 30% reduction in infant deaths within each race. Since the black infant mortality rate is twice the white infant mortality rate and black foreign-born mothers have much lower rates than black native-born mothers, it is likely that further improvement is possible among black infants.