Changes in the characteristics of families with Down's syndrome children.

A study of two cohorts of Down's syndrome children living at home in South Wales and born in 1964-66 and 1973-75 respectively shows that there are significant differences in the characteristics of their families. Parents of those born in the seventies were younger at the birth and of higher social class than parents with children born in the sixties. In the seventies the Down's syndrome child was more likely to be the couple's first child. Most changes result from the introduction of the amniocentesis test which is offered to older pregnant women. It is suggested that the social class differences are likely to be explained by changes in fertility in the various social classes.