SEVERE MENTAL RETARDATION IN CHILDREN IN A NORTHERN SWEDISH COUNTY.

This article focuses on severe mental retardation in children in a northern Swedish county. In an unselected series of children with severe mental retardation born in 1959-1970 in a northern Swedish county, an analysis was made of the incidence, prevalence, gestational age, birth-weight, associated central nervous system disorders, and aetiological and pathogenetic aspects. The children concerned were born in the period 1959-70, i.e. just before the gradual introduction in Sweden of prenatal diagnosis and other measures to prevent congenital disorders, and at the same time a period with a decrease in perinatal mortality.