Pyloric Stenosis in Twins

Abstract

Of 4 pairs of twins with pyloric stenosis, 3 were monozygous with 1 of each pair affected; 1 was dizygous with both twins affected. The literature lists 17 monozygous pairs of which 5 had only 1 twin affected, and 29 dizygous pairs of which 3 had both affected. The incidence of pyloric stenosis is the same in twins as in infants born singly.