Infantile hypertrophic pyloric stenosis in South Glamorgan 1970-9. Effects of changes in feeding practice.

In a retrospective analysis of cases of surgically confirmed infantile hypertrophic pyloric stenosis (IHPS) in South Glamorgan in the decade 1970-9 the incidence rose sharply in 1976 reflecting a general increase reported throughout Wales and from other parts of the United Kingdom. The increase was mainly among boys and although it occurred at a time when breast feeding had become more popular, it affected bottle fed infants more than breast fed infants. The apparent correlation between incidence of IHPS and incidence of breast feeding may coincidental and changes in infant milk formulae that became general in 1976 may be more important. An appreciable excess of first born infants with IHPS was noted but there was no correlation between birthweight and IHPS. Variations according to month of birth did not coincide with true seasonal variation.