Postterm delivery among African Americans, Mexican Americans and Whites in Chicago.

OBJECTIVES: The purpose of the present study was to examine the effect of individual-level and community-level risk factors on the postterm delivery rates of infants born to African-American, Mexican-American, and non-Latino White mothers; and to compare postterm delivery rates between these ethnic groups. DESIGN: This is a population-based study. METHODS: We performed stratified and multivariate logistic regression analyses on a linked dataset of 1992-1995 Illinois vital records, 1990 United States Census income data, and 1995 Chicago Department of Public Health information. Communities with one or more high-risk characteristics (low median family income or high rates of unemployment, homicide or lead poisoning) were classified as impoverished. RESULTS: In Chicago, African Americans (N = 85,978) had a postterm rate of 4.3/1,000 and Mexican Americans (N = 47,266) had a postterm rate of 3.6/1,000, compared to 2.3/1,000 for non-Latino Whites (N = 48,601); relative risk (ninety-five percent confidence interval) = 1.9 (1.5-2.3) and 1.6 (1.2-2.0), respectively. Maternal age, education, marital status, parity, and prenatal care usage were associated with ethnic group-specific postterm delivery rates. In a multivariate logistic regression model for non-impoverished mothers, the adjusted odds ratios of postterm delivery for African Americans and Mexican Americans were 1.0 (0.5-3.2) and 1.0 (0.6-1.7), respectively. CONCLUSIONS: We conclude that African Americans and Mexican Americans have greater postterm delivery rates than do Whites; however, commonly cited individual and community-level risk factors account for most of the disparity.

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.

Differential effect of ecologic risk factors on the low birthweight components of African-American, Mexican-American, and non-Latino white infants in Chicago.

This study explored the relationship between ecologic risk factors and infant birthweight. A stratified analysis was performed on all African-American, Mexican-American, and white infants born in Chicago in 1990. One half of African-American mothers (n = 26,799) resided in communities with multiple ecologic risk factors, yet their very low birthweight rates were unaffected by the number of these factors. By contrast, only 5% of Mexican-American mothers (n = 9913) and 5% of white mothers (n = 13,596) lived in communities with multiple ecologic risk factors. Their very low birthweights were twice that of infants born to mothers who resided in communities with no ecologic risk factors. These results indicate that ecologic risk factors affect the very low birthweight rates of Mexican Americans and whites but not African Americans.