Common birth defects in South African Blacks.

The prevalence rates of some of the common birth defects have been ascertained in a Black population in South Africa. The births of 29,633 infants were studied retrospectively from hospital records. The commonest defect was found to be polydactyly (10,4/1,000 births), and the other defects investigated were talipes equinovarus (1,55/1000 births), hydrocephalus (1,3/1,000 births), spina bifida and anencephaly (0,78 and 0,40/1,000 births respectively) and facial clefts (0,30/1,000 births). These rates were compared with those found in other population groups in South Africa and, in some cases, in other African countries and in Negro groups in the USA and Canada.