The incidence of Down syndrome in northern Finland with special reference to maternal age

Abstract
The incidence of live-born children with Down syndrome was found to be 1.73/1000 (1:578) in northern Finland over the yr 1965-1979. Despite a marked reduction in the proportion of older mothers, no significant change in the incidence was observed. Instead, an age-specific rise in the incidence for mothers aged 25-29 yr could be shown during the last 5-yr period in yr 1975-1979.