Background: We evaluated selected birth defects over a 9-year period to assess prevalence trends by selected maternal and infant factors.
Methods: Data were pooled from 11 population-based birth defects surveillance programs in the United States for children born between 1999 and 2007. Overall prevalence, as well as 3-year interval prevalence, was calculated for 26 specific birth defects, stratified by maternal age, maternal race/ethnicity, and infant sex. Average annual percent change (AAPC) was calculated for each birth defect. Poisson regression was used to determine change in AAPC, and joinpoint regression to identify breakpoints and changes in slope for prevalence of each defect over time.
Results: Between 1999 and 2001 and 2005 and 2007, four birth defects increased by 10% or more: coarctation of the aorta (17%), gastroschisis (83%), omphalocele (11%), and Down syndrome (10%). Among mothers <20 years of age, the gastroschisis AAPC increased 10.1% overall and, cross-classified by maternal race/ethnicity, the AAPC for mothers <20 years increased 9.2%, 25.7%, and 7.7% among non-Hispanic white (NHW), non-Hispanic black (NHB), and Hispanic mothers, respectively. A small increase in Down syndrome (AAPC 4.4%) was found for NHB mothers ≥35 years.
Conclusion: No significant trends in prevalence were identified for most birth defects. Gastroschisis prevalence increased significantly among NHW and NHB mothers <20 years of age, with the greatest increases in NHB mothers. Prevalence of Down syndrome among NHB mothers ≥35 years also increased slightly. Stratified results may suggest avenues of research in birth defect etiology and in evaluating prevention efforts. Birth Defects Research 109:1442-1450, 2017.© 2017 Wiley Periodicals, Inc.
Keywords: Down syndrome; birth defects; gastroschisis; joinpoint regression; prevalence; trends.
© 2017 Wiley Periodicals, Inc.