Long term androgen replacement therapy does not preclude gonadotrophin-induced improvement on spermatogenesis.

A previously hypophysectomized man with azoospermia, who was on androgen replacement therapy since 11 years, was studied with regard to his intratesticular steroid conversion capacity in vitro after which he was given combined hCG/hMG therapy. Before therapy a steroid conversion pattern similar to that seen in prepubertal boys was found, i.e. a high proportion of 20 alpha-dihydroprogesterone was produced while only smaller amounts of 17 alpha-hydroxyprogesterone was produced from the substrate 3H-progesterone. After only five weeks of hCG/hMG treatment, sperm counts and serum testosterone levels increased dramatically and a child was conceived. The steroid conversion pattern simultaneously switched to the mature, adult type with a low production of 20 alpha-dihydroprogesterone and large amounts of 17 alpha-hydroxyprogesterone being produced in vitro. Thus gonadotrophin substitution therapy may still be very effective after long term androgen replacement.