Correlation of the bovine cervical mucus penetration test with human spermcharacteristics in 1406 ejaculates

The bovine cervical mucus penetration test (BCMPT) was performed to determi ne its usefulness in screening the ability of sperm to successfully penetra te mucus in vitro. Ejaculates were obtained by masturbation from patients a ttending an infertility clinic. Routine semen analysis was performed using a microcomputerized multiple-exposure photography system. The BCMPT was per formed. Overall, the average penetration of the mucus was 38 +/- 0.46 mm. O f the 1406 ejaculates analyzed, 244 (17%) displayed a negative result (0-20 mm), 291 (21%) a questionable result (21-30 mm), and 871 (62%) a positive result (>30 mm). A highly significant (p < .001) correlation between mucus penetration distance and sperm MD (r = 0.541), MI (r = 0.484), count (r = 0 .475), motility (r = 0.448), velocity (r = 0.400) and morphology (r = 0.369 ) was observed. Overall, the finding of an abnormal semen parameter resulte d in a 34 +/- 5% accurate prediction of a negative or questionable BCMPT (< 30 mm), while a normal semen parameter resulted in a 90 +/- 4% accurate pre diction of a positive BCMPT (>30 mm). Sperm MD showed the strongest positiv e predictive value (98%), while morphology showed the greatest negative pre dictive value (50%). Of the 1406 samples, 25 +/- 2% of the samples with nor mal semen parameters displayed a negative BCMPT. Conversely, 6 +/- 2% of sa mples with abnormal parameters showed a positive BCMPT. The BCMPT successfu lly identifies a significant subpopulation of patients as having an inadequ ate penetration of mucus with otherwise normal semen characteristics.