Pregnancy outcome of Mexican-American women: The effect of generational residence in the United States

Objective: To determine whether duration of generational residence in the United States is associated with the pregnancy outcome of Mexican Americans. Design: This is a population-based study. Methods: Stratified analyses were performed on a data set of 1989-1991 Illinois computerized vital records of Mexican-American infants. Results: First generation (N=2,203) and second or higher (N=4,192) US-born Mexican-American women had infant low birth-weight rates of 7.5% and 6.1%, respectively, compared to 5.1% for Mexican-born women (N=39,050); relative risk=1.4 (1.2-1.7) and 1.2 (1.1-1.4), respectively. Among women with one or more high-risk sociodemographic characteristics (age less than 20 years, educational attainment less than 12 years, unmarried, high parity, or inadequate prenatal care), first generation (N=1,624) and second or higher generation (N=2,874) US-born Mexican-American women had infant low birth-weight rates of 8.3%. and 6.5%, respectively, vs 5.2% for Mexican-born women (N=33,625); relative risk = 1.6 (95% confidence interval [CI], 1.3-1.9) and 1.2 (95% CI, 1.0-1.4), respectively. Among women with the lowest sociodemographic risk profile, infant low birth-weight rates did not vary between the sub-groups. Conclusions: For second or higher generation US-born Mexican-American women, the rate of infant low birth weight does not exceed that of first generation US-born women; it actually approximates that of Mexican-born women across a broad range of sociodemographic characteristics.