title: Time trends in prevalence of gastroschisis in Texas, 1999 to 2011: Subgroup analyses by maternal and infant characteristics.
abstract: BACKGROUND
  The prevalence of gastroschisis, a birth defect of the abdominal wall, has been increasing in several areas around the world. Suggested risk factors for gastroschisis include maternal age, race/ethnicity, nativity, body mass index, and socioeconomic status.
  
  
  METHODS
  Data for cases of gastroschisis and live births were taken from the Texas Birth Defects Registry and Texas vital records for deliveries between 1999 and 2011. Prevalence by subgroups over time was calculated for: infant sex, maternal age, race/ethnicity, nativity, education, parity, plurality, body mass index, and payer type. Stratified, adjusted, and interaction analyses of the trends were conducted using Poisson regression. A joinpoint trend analysis was also conducted for each subgroup.
  
  
  RESULTS
  A total of 2,549 gastroschisis cases and 4,970,979 live births were delivered in 1999 to 2011, for an overall prevalence of 5.13 cases per 10,000 live births (95% confidence interval = 4.93-5.33). On average, the prevalence increased 4.8% each year; this overall time trend was statistically significant (p-value < 0.0001). The time trend remained significant after adjusting for all variables, except payer type. The stratified analysis showed the increasing time trend was significant in many of the subgroups. However, there were no significant differences in the magnitude of the time trends between subgroups according to the interaction analysis.
  
  
  CONCLUSIONS
  This study confirms the increasing prevalence of gastroschisis over the time period 1999 to 2011 in Texas. The results suggest that no population subgroups are experiencing a significantly different increase in gastroschisis prevalence over time than others.
authors.affiliation: Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, Texas.|University Health Science Center Houston School of Public Health, Austin Regional Campus, Austin, Texas.
authors.forename: Loc-Uyen T
authors.initials: LU
authors.lastname: Vo
authors.affiliation: University Health Science Center Houston School of Public Health, Austin Regional Campus, Austin, Texas.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Langlois
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005006:Ethnicity; D005260:Female; D020139:Gastroschisis / Q000145:classification* / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008297:Male; D008423:Maternal Age; D011247:Pregnancy; D015995:Prevalence; D012042:Registries; D012307:Risk Factors; D013781:Texas / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult
keywords: Texas; epidemiology; gastroschisis; interaction; maternal infant characteristics; prevalence; time trends