Population prevalence of Down's syndrome in the United Kingdom

Aim was to estimate the age and sex-stratified prevalence of Down's syndrome (DS) in the United Kingdom (UK) general population using a large primary care database.

Data source was the Clinical Practice Research Datalink. We divided the number of individuals with a record of DS present on 01/07/2014 by the total number of individuals, and computed Wilson's confidence intervals. Prevalence by age and sex was represented using local linear smoothing plots.

On July 1(st) 2014, 1159 females and 1317 males with DS were present in the data, corresponding to a prevalence of 5.9 per 10 000 (95% CI: 5.5; 6.2) in females and 6.8 (6.5; 7.2) per 10 000 in males. Prevalence of DS was increased in individuals aged 40 to 55 years compared to adjacent age groups.

A relative peak prevalence of DS at age 40-55 years may be attributed to the combined effects of a rise in life expectancy and the still limited availability of selective abortion.