Epidemiologic characteristics of congenital diaphragmatic hernia among 2.5 million California births, 1989-1997

BACKGROUND: Congenital diaphragmatic hernia (CDH) is a severe birth defect of unknown etiology. The aims of the current report were to extend the literature on the descriptive epidemiology of CDH and to determine whether its mortality rate decreased in California during the study period. METHODS: Using data from a large population-based registry, we ascertained 631 CDH cases from 1989 to 1997. We also classified cases as isolated or nonisolated based on the presence and type of major accompanying malformations. Approximately 2.5 million live and stillbirths occurred during the ascertainment period. Multivariate Poisson regression analysis was applied to examine the time trend and risk factors. RESULTS: The overall prevalence of CDH was 2.49 per 10,000 live and stillbirths and did not vary over the study period. Isolated cases, which accounted for 58% of cases, revealed a prevalence of 1.45 per 10,000. Heart malformations were the most frequent major anomalies accompanying CDH. We observed a lower risk of isolated CDH among blacks. Advanced maternal age groups had a higher risk for nonisolated CDH. Multiparous women tended to have a lower risk for nonisolated CDH. Male infants and multiple births had an increased risk for isolated and nonisolated CDH. Infant mortality was slightly decreased over the study period. CDH cases with additional anomalies had higher mortality rates than isolated cases. CONCLUSION: Our observations add to the relatively few population-based descriptive epidemiologic studies of the prevalence and mortality, and maternal and infant characteristics of CDH. Birth Defects Research (Part A) 76:170-174, 2006. (c) 2006 Wiley-Liss, Inc.