Congenital malformations and the problem of their control.

The possibility of preventing or reducing the prevalence of human congenital malformations is discussed in the light of current knowledge about their aetiology. The original data presented are derived from an epidemiological study of all the infants (92,982) born in the three years 1964-6 to women resident in a defined area of South Wales and all the congenital malformations (3,242) discovered in those infants by the second anniversary of their birth.