Prevalence of Down Syndrome Among Children and Adolescents in 10 Regions of the United States

OBJECTIVE: We aimed to estimate the prevalence of Down syndrome (DS) among children and adolescents aged 0 to 19 years in 10 regions of the United States. METHODS: This study was a cross-sectional analysis of live-born infants with DS during 1979-2003 from 10 population-based birth defects registries in the United States. We estimated the prevalence of DS at birth and among children aged 0 to 19 years in each region and in all regions pooled. The prevalence of DS among children and adolescents was calculated overall and according to age group, race/ethnicity, infant gender, and presence of a major heart defect. RESULTS: From 1979 through 2003, the prevalence of DS at birth increased by 31.1%, from 9.0 to 11.8 per 10 000 live births in 10 US regions. In 2002, the prevalence among children and adolescents (0-19 years old) was 10.3 per 10 000. The prevalence of DS among children in a given age group consistently increased over time but decreased with age within a given birth cohort. The pooled prevalence of DS among children and adolescents was lower among non-Hispanic black individuals and other racial/ethnic groups compared with non-Hispanic white individuals; it was also lower among females than males. CONCLUSIONS: This study provides prevalence estimates of DS among children and adolescents from 10 US regions. These estimates varied according to region, race/ethnicity, and gender, suggesting possible variation in prevalence at birth or in survival rates on the basis of these characteristics. Pediatrics 2009;124:1565-1571