The role of the epididymis in human infertility.

This review describes the role of the epididymis in human infertility, by analysing the results of epididymovasostomies which confirm that the more distal the site of obstruction the greater the chance of fertility. The use of epididymal spermatozoa for in vitro fertilization (IVF) yielded poor results in contrast to intracytoplasmic sperm injection using either epididymal or testicular spermatozoa. The nature of the pathology causing obstructive azoospermia is examined reviewing in particular the possible role of mercury toxicity in Young's syndrome. This review describes the results of studies that show that the level of obstruction within the epididymis is correlated with the presence of sperm antibodies and distal obstructions are associated with the presence of sperm antibodies. The demonstration that necrozoospermia decreases with increased sperm transport through the epididymis, when combined with the observation of normal testicular sperm morphology, represents the basis for the disorder termed epididymal necrozoospermia. However, to date the nature of the epididymal pathology causing this disorder remains obscure.