Researchers believe that the increased temperature within the abdomen harms the enzymes and proteins that are responsible for normal sperm production. Sperm quality may be especially poor in men who have bilateral undescended testes. Cryptorchidism is a common childhood disorder. These figures are evidence of the late occurrence of testes descent during fetal growth within the womb. Yet incomplete testicular descent is not just a physical abnormality.
Fertility appears to improve among men who receive therapy for cryptorchidism before puberty.
Most cryptorchidism cases have no known cause. Yet most experts recommend some form of therapeutic management between the child's first and second birthdays. In the United States, a preferred approach to therapy for unilateral cryptorchidism is surgical placement of the testis in a normal scrotal position before the second birthday. By contrast, European physicians generally rely on hormone therapy as the primary treatment for all patients with cryptorchidism. Unfortunately, once the testes have been injured by cryptorchidism, such injury usually cannot be corrected.