Semen parameters and fertilization of human oocytes in vitro: a multivariable analysis.

Semen parameters in 195 couples undergoing in vitro fertilization and embryo transfer were studied using multivariable analysis. Semen parameters that correlated most closely with reduced ability to fertilize apparently mature oocytes were a slow rate of foreward progression of sperm and the presence of excess numbers of white cells in semen. In men with semen parameters within the normal range, the hamster egg penetration assay (HEPA) test did not add additional predictive power. In men with suspected semen abnormalities, however, a low attachment rating added some, but minimal, predictive value. None of the predictive methods reported thus far in this or other studies offers sufficient accuracy to reliably identify the men who will prove infertile for in vitro fertilization treatment.