An update on non-obstructive azoospermia; a narrative review

: Azoospermia can stem from either an obstructive issue or a non-obstructive problem originating in the testes. Distinguishing between these two root causes relies on clinical evaluation of testis size and consistency, hormone testing of FSH levels, and genetic analysis looking at chromosomes, Y chromosome microdeletions, and genes involved in hypogonadotropic hypogonadism. NOA encompasses both primary testicular failure where sperm production is impaired, as well as secondary failure driven by hypothalamic or pituitary dysfunction leading to inadequate gonadotropin levels. The treatment approach for NOA is still largely empirical, lacking definitive evidence-based guidelines. However, for cases of hypogonadotropic hypogonadism specifically, gonadotropin replacement with hCG and recombinant FSH is the primary established treatment aimed at improving semen quality and increasing chances of conception. GnRH therapy can be added for men who don't respond adequately to gonadotropins alone. While high-level clinical data is scarce, there are some indications that combining aromatase inhibitors with gonadotropin therapy may enhance outcomes for men requiring surgical sperm retrieval procedures. Overall, this review summarizes the current understanding of the causes, treatments, and clinical management of non-obstructive azoospermia.