Abstract / Summary
Male factor infertility contributes to approximately 50% of reproductive failure in couples worldwide. We conducted a narrative critical review synthesizing evidence from systematic reviews, meta-analyses, randomized controlled trials, and clinical practice guidelines on reversible and irreversible causes of male infertility, examining hormonal, surgical, pharmacological, lifestyle, and drug-induced etiologies. The majority of identifiable etiologies demonstrate some degree of reversibility. Varicocele (prevalence 25–40% in infertile men) achieves natural pregnancy rates of 30–40% after varicocelectomy. Hypogonadotropic hypogonadism responds to gonadotropin therapy with spermatogenesis induction in 90–95% of cases. Obstructive azoospermia achieves ductal patency rates of 85–97% with microsurgical reconstruction. Male accessory gland inflammation is reversible with prompt antibiotic therapy. Spermiotoxic drug exposures—including anabolic-androgenic steroids, sulfasalazine, and chemotherapy—show variable reversibility depending on agent and duration of exposure. Normogonadotropic normotestosteronemic oligozoospermia represents a commonly encountered phenotype that may respond to empirical medical therapy. Lifestyle modifications demonstrate measurable benefits in selected patients. Irreversible causes include Klinefelter syndrome, Y-chromosome AZFa/b microdeletions, and severe post-chemotherapy damage. Systematic andrological evaluation, including comprehensive drug history, is essential to identify treatable causes and guide clinical management.