Spina bifida and anencephaly in the Cape.

In the first phase of a programme for the prevention of neural tube defects at a population level, information has been obtained concerning 285 infants born with open neural tube defects. As in other parts of the world, the months of conception of affected infants clustered in the second quarter of the year and the majority of the parents were members of lower income groups. In the years 1975-1977, the incidence of anencephaly and spina bifida in White South African patients was similar to that generally encountered in Western Europe. However, in the non-White populations the separate and combined incidence were significantly lower. It is emphasized that these are preliminary figures and that they might be subject to ascertainment biases.