The relationship of abnormal semen parameters to male fertility.

To what extent do standard semen parameters reflect male fertility? A review of many studies over the last 35 years relating pregnancy rate to sperm counts in 'fertile' and 'infertile' couples indicates that standard semen parameters, though much maligned of late, are useful in evaluating the degree of 'male factor' in an infertile couple. However, 'male factor' is quite compatible with fertility in a couple if the wife is very fertile. Oligoasthenozoospermia is, unfortunately, for the most part, an untreatable condition. Yet, vigorous treatment of the wife may still result in pregnancy despite very poor semen quality. Higher sperm counts in an infertile couple are associated with higher pregnancy rates. But in the majority of infertile couples in whom the sperm count is poor, female factors also exist that prevent conception. If the wife were very fertile, she would have become pregnant despite her husband's oligozoospermia, and they would never have seen a physician for infertility. Thus, pregnancy can be achieved with very low sperm counts either by treatment of the wife, IVF, GIFT or ZIFT procedures.