Beyond the clinical classification of azoospermia: opinion.

There is an ongoing debate regarding the appropriate classification of azoospermia. This manuscript reviews the rationale for the current classification of azoospermia and how to effect a change if there is a need to do so. The current classification of azoospermia into obstructive and non-obstructive is because azoospermia due to ejaculatory duct dysfunction and hypogonadotrophism are extremely rare. Though the use of clinical protocols (defective spermatogenesis, genital tract obstruction, ejaculatory duct dysfunction, hypogonadotrophism or pre-testicular, testicular and post-testicular) may be useful in selecting patients for appropriate treatment, no study has shown that they provide a better method of classification of azoospermia than the current approach. There is increasing evidence of a genetic basis of male infertility as well as the evidence that men's fertility potential may be classified genetically. Moreover, genetic disorders may be transmitted to the offspring and their presence in infertile couples may affect treatment outcome. It is therefore useful to explore a genetic classification of azoospermia.