Azoospermia is classified as obstructive azoospermia (OA) or non-obstructive azoospermia (NOA), each having very different etiologies and treatments. The etiology, diagnosis, and management of azoospermia were reviewed and relevant literature summarized. Differentiation between these two etiologies is of paramount importance and is contingent upon thorough history and physical examination and indicated laboratory/genetic testing. OA occurs secondary to obstruction of the male reproductive tract, and is diagnosed through a combination of history/physical examination, laboratory testing, genetics (CFTR for congenital OA), and imaging studies. NOA (which includes primary testicular failure and secondary testicular failure) is differentiated from OA by clinical assessment (testis consistency/volume), laboratory testing (FSH), and genetic testing (karyotype, Y chromosome microdeletion, or specific genetic testing for hypogonadotropic hypogonadism). For obstructive azoospermia, management includes microsurgical reconstruction when feasible using microsurgical vasovasostomy or vasoepididymostomy. Microsurgical epididymal sperm aspiration with in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) is utilized for those cases not amenable to reconstruction. NOA management includes medical management for congenital hypogonadotropic hypogonadism and microdissection testicular sperm extraction with IVF/ICSI for appropriate candidates based on laboratory/genetic testing. Overall, this important review provides an updated summary of the most recent available literature describing etiology, diagnosis, and management of azoospermia.
