Male infertility: diagnosis and treatment.

The evaluation of the subfertile male starts with the basic history and physical examination, which often provide indication of probable cause. Aside from analysis of properly collected semen, most cases require very few tests. Etiology can be classified as pretesticular, testicular, and post-testicular. Treatment can be more specific if a definite cause is found. Unfortunately, about 25% of patients are idiopathic, and non-specific treatments generally yield unacceptably low conception rates. Improvement will occur as more becomes known, through animal research and clinical application, about the physiology of spermatogenesis and the pathological processes that can affect it.