Male infertility: the impact of assisted reproductive technologies

Spermatozoal abnormalities are present in up to 40% of infertile couples. Multiple etiologies may be responsible for these disorders, including pretesticular, testicular, and ductal causes. An adequate andrologic consultation, including history, physical examination, and repeated semen analysis, should be performed routinely in these cases. Evaluation of the basic sperm parameters, including sperm concentration, motion parameters (as evaluated by computer-assisted semen analysis), and sperm morphology (as judged by strict criteria), constitute the first obligatory step for a critical evaluation of male factor patients. Patients in whom fertilization disorders are suspected should be evaluated through bioassays of sperm-oocyte interaction, including the heterologous sperm penetration assay and hemizona assay, a bioassay of sperm-zona binding capacity highly predictive of in vitro fertilization outcome. Male disorders can be subjected to specific therapies (surgical or medical), or to empiric therapeutic modalities. Assisted reproductive technologies have enhanced our understanding of the physiopathology of spermatozoal disorders and also have ostensibly improved pregnancy rates in male factor patients.