The Role of Hormone Stimulation in Men With Nonobstructive Azoospermia Undergoing Surgical Sperm Retrieval.

Nonobstructive azoospermia, (NOA) is the most common cause of azoospermia. NOA is characterized by hypergonadotropic hypogonadism, testicular failure, and impaired spermatogenesis. The recent development of surgical sperm retrieval techniques such as microsurgical testicular sperm extraction (mTESE) has, for the first time, allowed some men with NOA to father biological children. It is common practice for endocrine stimulation therapies such as gonadotropins, selective estrogen receptor modulators (SERMs), and aromatase inhibitors to be used prior to mTESE to increase intratesticular testosterone synthesis with the aim of improving sperm retrieval rates; however, there is currently a paucity of data underpinning their safety and efficacy. We present 2 cases of men with NOA undergoing endocrine stimulation therapy and mTESE. We also discuss the current evidence and controversies associated with the use of hormonal stimulation therapy in couples affected by this severe form of male infertility.