'Value of FSH and inhibin-B measurements in the diagnosis of azoospermia'--a clinician's overview.

Azoospermia can be either of obstructive ctiology or due to the testis' failure to initiate or maintain spermatogenesis. FSH acts through its receptor at Sertoli cell level and modulates spermatogenesis initiation and maintenance. Inhibin B is a Sertoli cell product expressing the functional capacity of the cell and in an indirect way the state of seminiferous tubule activity. Both FSH and inhibin B differentiate clearly testicular from extra-testicular pathology of azoospermia while, none of these hormones has been convincingly established as predictory index for the finding of spermatozoa in TESE.