Cryptorchidism

Cryptorchidism is the absence of one or both testes from the scrotal sac because normal hormonal and mechanical descent failed during fetal development. The testis may be located in the abdomen, along the inguinal canal, or outside its usual path; “nonpalpable” means it cannot be felt on examination, not that it is definitely absent. Descent places the testis in the cooler scrotal environment required for normal germ-cell maturation. A testis retained in the abdomen or groin is exposed to higher temperatures, which can impair spermatogenesis over time. This explains why fertility effects are more pronounced when both testes are undescended: uncorrected unilateral disease is associated with a 15–20% reduction in fertility, whereas bilateral disease may reduce fertility by up to 80%. Cryptorchidism also increases the risk of testicular malignancy by approximately two- to eight-fold compared with a descended testis. Orchiopexy lowers that risk and makes the testis easier to examine, but it does not restore the risk to that of a naturally descended testis. In Canada, the prevalence stabilises at approximately 0.7–1.0% of male infants by one year of age....