[Does sperm penetration in bovine mucus provide additional information to the "classical" spermiogram and motility characteristics?].

In vitro bovine cervical mucus penetration tests (Penetrak) were performed in 30 patients from our fertility clinic and in 33 healthy volunteers with normal semen characteristics. After 90 minutes maximum penetration by sperm (mm) was measured using a capillary filled with bovine midcycle cervical mucus. At the same time classical (sperm motility [%], concentration [mill/ml] and morphology [% oval heads] ) and computerized semen analyses (Cell Soft) were performed (mean velocity [micron/s], lateral head displacement [micron], beat frequency [Hz] and mean linearity). Multiple regression analysis of the depth of sperm penetration in cervical mucus (mm) yielded those semen parameters which allowed correct prediction of the penetration test in 54% of cases. Sperm concentration, morphology, motility and mean velocity alone accounted of 53% of the predictions. In 46% of cases the outcome of the cervical mucus penetration test could not be predicted, regardless of whether classical or computerized semen analysis was performed. This suggests that factors other than those described above must play a role in this aspect of sperm function.