Sperm Retrieval Rates in Non-obstructive Azoospermic Men Subjected to Gonadotropin Therapy

Azoospermia is defined as the complete absence of spermatozoa in the ejaculate. Two-thirds of azoospermic patients have non-obstructive azoospermia (NOA); the latter comprises up to 10% of infertile men overall. NOA is an untreatable testicular disorder associated with spermatogenic failure and is the most severe male infertility phenotype. Among the available surgical sperm retrieval techniques, microdissection testicular sperm extraction (micro-TESE) is the procedure of choice due to its high sperm retrieval success rates (SRR), minimal tissue extraction, and low complication rates. Even with the use of micro-TESE, the likelihood of retrieving sperm in patients with NOA remain suboptimal (40% to 60%). Hypogonadism is detected in approximately half of the patients with NOA. Given the role of intratesticular testosterone (ITT) levels for spermatogenesis, some studies have explored the clinical utility of testosterone optimization by medical therapy before sperm retrieval. Moreover, some investigators have hypothesized that the follicle-stimulating hormone (FSH) reset might increase the expression of FSH receptors and improve Sertoli cell function. Hormonal therapy with human chorionic gonadotropin (hCG) has been shown to improve ITT production and decrease FSH levels in patients with NOA. The investigators, therefore, designed an observational cohort study aiming to evaluate whether hormone stimulation with gonadotropins (e.g., hCG alone or combined with FSH) previous to micro-TESE increases sperm retrieval rates in hypogonadal infertile men with NOA, candidates for sperm retrieval. The investigators hypothesize that optimizing ITT production and resetting FSH levels may improve spermatogenesis and successful sperm recovery.