EVALUATION OF BOVINE CERVICAL-MUCUS PENETRATION AS A TEST OF HUMAN SPERMATOZOAL FUNCTION FOR AN INVITRO FERTILIZATION PROGRAM

Thirty-two couples participating in an in vitro fertilization (IVF) programme were evaluated as regards the prognostic value on fertilization of spermatozoal performance through flat capillary tubes filled with standardized mid-cycle bovine cervical mucus (Penetrak, Serono Diagnostics, Surrey, UK). A statistically significant correlation (P < 0.033) was observed between the distance travelled by the neat spermatozoa in the mucus and the % penetration of oocytes at IVF. There were also significant correlations between motility and progression (P < 0.004) and a borderline correlation between progression and the Penetrak results (P < 0.098). There was no significant difference between the Penetrak distances travelled between the 9 who conceived (33.4 mm) and the 23 who did not (29.9 mm). While the test does add to the knowledge of fertilization potential, the results extrapolated to a larger series would give false positive rates of 25% and false negative rates of 11%. The absence of a clear end point renders the Penetrak mucus penetration test insufficiently accurate to be used as a main measure of the male factor when advising for or against IVF therapy.