Clinical and biological characteristics of infertile men with a history of cryptorchidism.

Out of 85 fertile and 1014 infertile men, two (2.4%) and 95 (9.4%) respectively had a history of cryptorchidism. Thus cryptorchidism appears to be a risk factor for fertility since this difference was significant. Further comparisons showed that the volume of a former cryptorchid testis was smaller than the contralateral normally descended one and that sperm output/concentration was more impaired in bilateral than in unilateral cryptorchidism. A retractile testis, defined as a testis reported by the patient to be spontaneously and regularly, i.e. at least once a week, ascending up into a supra-scrotal position, was more frequent in infertile men with a history of cryptorchidism than in fertile men. Retractility was more frequent on the cryptorchid side, and was found more frequently after hormonal than after surgical treatment. Independently of all epidemiological and clinical parameters studied, retractility was associated with a lower sperm output. Among the infertile men with a history of cryptorchidism, 45% had an abnormally high scrotal temperature. This abnormal temperature represented a pejorative risk factor for fertility in this group, since it was associated with a more severely impaired spermatogenesis and a higher incidence of primary infertility than in infertile men with a history of cryptorchidism but normal scrotal temperatures.