Infantile pyloric stenosis.

It would seem, from the studies of Carter and Powell (1954) and of McKeown, MacMahon and Record (1952), that both genetic and environmental factors play a part in the aetiology and development of infantile pyloric stenosis. The latter group of workers have stressed the importance of postnatal environmental influences. Their studies, based on data derived from more than 1,000 cases treated in the Children's Hospital, Birmingham, between 1940 and 1951, showed that symptoms, on average, developed later in babies born in hospital than in those delivered at home, and in first-born than in those born subsequently. In an earlier survey, based on 578 cases operated on between 1945 and 1950, they (McKeown et al., 1951c) had also found that the size of the tumour was roughly proportional to the age of the baby at operation. These observations, coupled with the rarity with which the tumour is found at birth, strongly suggested not only that the growth of the tumour was a post-natal phenomenon, but also that its rate of growth was conditioned by post-natal factors. The purpose of the present study was first to confirm, by direct measurement of the tumour at operation, that its size was indeed proportional to the age of the baby; secondly to enquire into possible post-natal influences determining its rate of development; and thirdly to attempt to evaluate the role of genetic factors.