The use of epididymal spermatozoa in assisted reproduction.

The use of epididymal spermatozoa in assisted reproduction (ART) permits fertility in men with surgically irremediable obstructive azoospermia. When used for conventional IVF (sperm-oocyte co-culture), epididymal spermatozoa show reduced fertilization and pregnancy rates (compared with ejaculated spermatozoa from men with a range of spermatogenic disorders) as evidence of their functional immaturity. However, when used with intracytoplasmic sperm injection (ICSI) either fresh or frozen-thawed epididymal spermatozoa produce ART success rates similar to those of ejaculated spermatozoa. The clinical place of epididymal sperm retrieval for ICSI has come under review as a result of data showing similarly good outcomes with testicular spermatozoa obtained by needle aspiration. In Australia ICSI using epididymal or testicular spermatozoa is an increasingly favoured option for vasectomy-related infertility and in other types of obstructive azoospermia for a number of reasons including better pregnancy outcomes, the less invasive nature of the procedures and less expense involved; however, this cost-benefit analysis will vary in other health systems.