Abnormal sperm morphology and function in the fathers of hypospadiacs.

A lower motility of spermatozoa and a higher incidence of abnormal sperm morphology were found in 25 fathers of hypospadiacs compared with those of 50 fathers who produced children who were not hypospadiacs. Subfertility of fathers may result in a higher risk of hypospadias in offspring and as subfertile males now represent a higher proportion among fathers, owing to the improved efficacy of infertility treatment, this may explain the increased occurrence of hypospadias. Our relaxed-selection hypothesis, which states that there is a redistribution in the number of children born to fertile and infertile (subfertile) couples, may account for the increasing number of other defects and cancers of male genitalia observed today and the fall in sperm counts.