Delayed treatment of undescended testes may promote hypogonadism and infertility.

CONTEXT: Undescended testes at birth may be caused by testosterone deficiency during fetal development. It is unclear whether the process of failed descent contributes to permanent endocrine impairment.

OBJECTIVES: To evaluate the impact of age at treatment of undescended testes on endocrine and spermatogenic testicular function in middle-aged men.

PATIENTS AND METHODS: Reproductive hormone and semen data of 357 men with previously undescended testes were evaluated with respect to age at correction of testicular position and compared to those of 709 controls with eutopic testes at birth and normozoospermia.

RESULTS: Men with undescended testes had higher mean Luteinizing Hormone levels (p < 0.0001) and lower mean testosterone levels (p = 0.003) compared to controls. They also had lower bi-testicular volumes, higher Follicle Stimulating Hormone levels, and lower sperm concentrations (all p < 0.0001). Lowest mean sperm concentrations were found in subjects with bilateral undescended testes. Normal sperm concentrations were found in 21 % of cases (in 27 % of men with unilateral and in 12 % with bilateral undescended testes), while oligozoospermia was diagnosed in 44 %, and azoospermia in 35 % (in 28 % with unilateral, 46 % with bilateral undescended testes). Subjects with reduced semen quality had higher gonadotropin levels than those with normozoospermia. Age at correction (median: 6 years (1-39)) was inversely correlated with bi-testicular volumes and sperm concentrations, and positively correlated with FSH and LH, but not with serum testosterone.

CONCLUSION: Latent, rarely decompensated hypogonadism is a potential long-term consequence of undescended testes, besides infertility and testicular cancer, preferentially affecting subjects with delayed or unsuccessful correction of testicular position. Impaired Leydig cell function is likely to contribute to compromised fertility. These observations support correction of cryptorchidism during early infancy.