The Geography of spina bifida in England and Wales

Spina bifida is a generic term describing malformations of the central nervous system in infants. Over 1000 cases of spina bifida were notified in England and Wales in 1971, but this had declined to 360 in 1985, partly due to maternal screening and the acceptance of therapeutic abortion. This paper reviews hypotheses about the causes of spina bifida and uses Poisson probabilities and regression techniques to examine spatial variations in the prevalence of spina bifida between 1983 and 1985. Differences in the maternal screening policies of health authorities are highlighted as an important factor, indicating that the study of 'geographical epidemiology' cannot be divorced from issues of health care.