Differing postneonatal mortality rates of Mexican-American infants with United-States-born and Mexico-born mothers in Chicago

Objectives: This study sought to determine the relationship between maternal nativity and the postneonatal mortality rate of urban Mexican-American infants. Design: This is a population-based study. Methods: Stratified and logistic regression analyses were performed on a data set of 1992-1995 computerized birth-death records of all Mexican-American infants born to Chicago residents with appended 1990 United States Census income and 1995 Chicago Department of Public Health data. Results: In Chicago, Mexican-American infants (N = 10,599) of US-born mothers had a postneonatal mortality rate of 3.2/1,000 compared to 2.1/1,000 for infants (40,813) of Mexico-born mothers; relative risk (95% confidence interval) equaled 1.5 (1.0-2.3). The adjusted odds ratio of postneonatal mortality was 1.4 (1.1-1.9) for Mexican-American infants of US-born mothers. The mortality rate due to preventable causes (sudden infant death syndrome, homicides, non-intentional injuries, and infections) for Mexican-American infants of US-born mothers was twice that of infants of Mexico-born mothers; relative risk (95% confidence interval) equaled 2.2 (1.3-3.8); this nativity differential persisted in non-impoverished communities. Conclusion: The postneonatal mortality rate of urban Mexican-American infants with US-born mothers exceeds that of infants with Mexico-born mothers. This nativity disparity is attributable to preventable causes.