Twenty-year trends in prevalence and survival of Down syndrome

The aims of this study were (1) to determine trends in total prevalence and live birth prevalence of Down syndrome, (2) to analyse trends in factors likely to influence this prevalence and (3) to determine 1-year survival in Down syndrome. A retrospective review was made of prospectively collected data on all cases of Down syndrome within a malformation registry born in 1985–2004. Down syndrome affected 1188 pregnancies among 690 215 live births (1.72 per 1000 total births). The proportion increased over 20 years from 1.3 to 2.5 per 1000 total births ( P