Fertility in experimental unilateral cryptorchidism.

Unilateral cryptorchidism was induced in Wistar rat pups within 48 hours of birth. Evaluation of fertility was subsequently assessed at 50, 100, and 150 days of age by paternity and daily sperm production. The descended scrotal testis was demonstrated to have a significantly diminished rate of sperm production at 150 days. Paternity studies failed to reflect this dysfunction, cryptorchid and sham-operated control animals having a 58% and 80% ability to produce offspring (P = .44).