Challenges in the Management of Nonobstructive Azoospermia

Nonobstructive azoospermia (NOA) is defined as an absence of sperm secondary to an impairment in spermatogenesis. NOA can be classified as pre-testicular (hypogonadotropic hypogonadism) or testicular (spermatogenic failure) depending on the underlying problem. Due to the broad differential diagnosis and large proportion of men with idiopathic NOA, management of NOA presents many unique challenges. Evaluation of NOA consists of a thorough history, physical exam, semen analysis, hormonal evaluation, and genetic evaluation. Hormonal therapy consists of various medications including gonadotrophins, aromatase inhibitors, and selective estrogen receptor modulators. Hypogonadotropic hypogonadism may be managed successfully with hormonal therapy by stimulating intratesticular testosterone (ITT) production. Management of hypogonadotropic hypogonadism with hormonal therapy may be followed by surgical sperm retrieval if hormonal therapy alone is unsuccessful. The use of hormonal therapy in men with spermatogenic failure is controversial, and there is conflicting evidence for its utility. Typically, testicular sperm extraction is the mainstay of managing NOA caused by spermatogenic failure. There are several factors that have been investigated as potential predictors of successful sperm retrieval, including patient, clinical, and hormonal considerations. This chapter provides an overview of management considerations in men with NOA, including its challenges.