Maternal nativity as a risk factor for gastroschisis: a population-based study.

BACKGROUND The prevalence of gastroschisis is increasing in many parts of the world, although the etiology is largely unexplained. Young maternal age has been the only consistently identified, strong risk factor. The objective of this study was to examine the role of maternal nativity in relation to other suspected risk factors for gastroschisis in Florida. METHODS We conducted a retrospective cohort study of singleton infants born in Florida from 1998-2003. Gastroschisis cases were identified from the Florida Birth Defects Registry. Demographic and perinatal data were obtained from birth records. Multivariable Poisson regression was used to estimate adjusted prevalence ratios (PRs) and 95% confidence intervals (CIs) for each factor of interest. RESULTS The 6-year birth prevalence of gastroschisis was 3.26 per 10,000 live births, and the annual rate increased 41% during the study period. In addition to maternal age and marital status, maternal race/ethnicity and nativity were significantly associated with the risk of delivering an infant with gastroschisis. Compared with non-Hispanic white women, non-Hispanic black women had the lowest risk of delivering an infant with gastroschisis (PR, 0.19; 95% CI, 0.13-0.26), followed by Hispanic women (PR, 0.60; 95% CI, 0.43-0.83). Women born outside the United States were significantly less likely than U.S.-born women to deliver an infant with gastroschisis (PR, 0.59; 95% CI, 0.41-0.86). CONCLUSIONS Although young maternal age remains a strong significant risk factor for gastroschisis in Florida, other factors such as maternal race/ethnicity and nativity could be important in explaining the increasing prevalence of gastroschisis.