Medical management of non-obstructive azoospermia: A systematic review

While most men with non-obstructive azoospermia (NOA) are not amenable to medical treatment, some men can be treated effectively with hormonal therapy, prior to considering surgery. In some cases, hormonal therapy alone can treat NOA, without the need for surgery. In other cases, correction of a potential hormonal imbalance can enhance the chances of success of surgical sperm retrieval (SSR), with either conventional or microdissection testicular sperm extraction. Abnormal testicular function and low androgen levels can result from a primary dysfunction, a medical or surgical condition, or from an exogenous factor, and should be managed prior to more invasive interventions. Even men with normal androgen levels may benefit from hormonal therapy before sperm retrieval. Moreover, SSR may cause testicular injury and aggravate the pre-existing situation. If surgical extraction of sperm fails, it leaves the patients with less satisfactory options, like donor sperm or adoption. Therefore, it is the role of the infertility specialist to be vigilant and identify reversible causes of NOA, such as hormonal imbalance, prior to considering surgery. In the present paper we will systematically review the literature and highlight the available conventional medical regimens, as well as experimental ones. Abbreviations: ART: assisted reproductive technology; CAH: congenital adrenal hyperplasia; EAU: European Association of Urology; hCG: human chorionic gonadotrophin; HH: hypogonadotrophic hypogonadism; hMG: human menopausal gonadotrophin; IUI: intrauterine insemination; micro-TESE: microdissection testicular sperm extraction; NOA: non-obstructive azoospermia; OR: odds ratio; SCO: Sertoli-cell only; SERM: selective oestrogen receptor modulator; SRR: sperm retrieval rate; SSC: spermatogonia stem cell; TART: testicular adrenal rest tumour; WMD: weighted mean difference.