Seasonal incidence of congenital disease in Birmingham

Summary Data are advanced showing that considerable seasonal variations in the incidence of some common congenital malformations can be demonstrated. It is suggested that this is probably a feature common to many congenital malformations, although its demonstration will usually require extensive data. * The author is grateful to Dr G. R. Fraser for allowing him to examine his very extensive data on cleft palate, cleft palate and hare‐lip, and hare‐lip. These show no suggestion of any appreciable seasonal variation.