Effects of Unilateral Cryptorchidism on Contralateral Epididymal Sperm Quality, Quantity and Fertilizing Capacity

The effect of unilateral cryptorchidism on ipsilateral testicular function has been well studied both in human and experimental animals. However, the effect of unilateral cryptorchidism on contralateral testicular function remains unclear. To evaluate the effect of left cryptorchidism on right testicular function, 3 groups of immature male rats were used: group A, left cryptorchid rats; group B, sham operated rats and group C, orchidopexed rats. Ten weeks post-cryptorchidism induction, right testicular versus intraabdominal temperature difference (RΔT), bilateral epididymal sperm content and motility, bilateral testicular weight, fertility rate in vivo and in vitro, and serum testosterone responses to human chorionic gonadotropin stimulation were tested. Most of the above parameters were significantly lower in group A than in group B and significantly higher in group C than in group A. The current findings suggest that there is a detrimental effect of unilateral cryptorchidism on sperm fertilizing capacity in vitro not only on the ipsilateral side but also on the contralateral side.