Hypospadias--genetics, epidemiology and other possible aetiological influences.

Questionnaires relating to 515 children with hypospadias were evaluated in respect of course of pregnancy, family history and epidemiology. The domiciles were more often in rural areas as compared to the average population in South Bavaria. A seasonal trend favouring the six months' period December to May could be observed. Children with hypospadias especially of higher degree were more often preterm and more frequently firstborn. 59 children (11.5%) had associated malformations particularly of the urogenital tract. Mothers of children with high-degree hypospadias were remarkably young and conspicuously often wives of farmers. There was a clear correlation between the degree of hypospadias and threatened abortion, drugs, sexhormones and other disturbances during early pregnancy. The trend to lower age classes could be also observed in fathers. The incidence of hypospadias in fathers was 5-fold and in brothers 30-fold above average. The risk of recurrence was 1.4% if the father had a hypospadia and 6% if a brother had hypospadias. The incidence of other malformations did not seem to be enhanced in relatives.