Potatoes and Spina Bifida

Abstract

Anencephaly and spina bifida (ASB) are important human malformations: four in every 1000 births, including stillbirths, have one or other of these major birth defects in the UK as a whole (0.4%). In the Western world, spina bifida, though usually more frequent than anencephaly, behaves more or less the same as anencephaly in its epidemiology. Where one is common, the other is common, e.g. in Ireland. Where one is rare, the other is rare, e.g. in London, where it is about five times rarer than in Belfast. When one is common, the other is common, e.g. in winter, and a bad year for one tends to be a bad year for the other. Both afflict the poor more than the wealthy by a factor of about four. Both occur at higher rates in older mothers and among those mothers with more children. The previous birth of an anencephalic leads the mother to have a 5% risk of anencephaly or spina bifida in a later pregnancy; the previous birth of a spina bifida child also leads to a comparable risk of either malformation.