title: Epidemiologic characteristics of congenital diaphragmatic hernia among 2.5 million California births, 1989-1997.
abstract: 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.
  
  
  CONCLUSIONS
  Our observations add to the relatively few population-based descriptive epidemiologic studies of the prevalence and mortality, and maternal and infant characteristics of CDH.
authors.affiliation: March of Dimes Birth Defects Foundation, California Birth Defects Monitoring Program, Berkeley, California 94710, USA. wya@cbdmp.org
authors.forename: Wei
authors.initials: W
authors.lastname: Yang
authors.forename: Suzan L
authors.initials: SL
authors.lastname: Carmichael
authors.forename: John A
authors.initials: JA
authors.lastname: Harris
authors.forename: Gary M
authors.initials: GM
authors.lastname: Shaw
mesh_terms: D000015:Abnormalities, Multiple; D002140:California / Q000453:epidemiology; D005260:Female; D006548:Hernia, Diaphragmatic / Q000453:epidemiology* / Q000401:mortality; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D015995:Prevalence; D012307:Risk Factors; D015996:Survival Rate