The use of hens' egg white as a substitute for human cervical mucus in assessing human infertility.

Semen samples from 179 patients with longstanding infertility were allowed to penetrate capillaries filled with a fraction of fresh hens' egg white (HEW) as a substitute for cervical mucus (CM) for the in-vitro sperm-cervical mucus penetration test (SCPMT). Results were correlated with those obtained from human CM (HCM) used in parallel on the same semen sample, compared to results of sperm analysis and post-coital testing (PCT) and analysed for their prognostic value for a subsequent pregnancy in a prospective study. The overall pregnancy rate after 6 months was 26.3% (47/179). Whereas routine semen analysis (semen volume, pH, sperm count, progressive motility, morphology and fructose concentration) did not differentiate between patients who achieved pregnancy and those who did not, significant differences were found for the penetration distance (P less than 0.02) and the motility grade of sperm in HEW (P less than 0.02). Although the mean sperm velocity in HEW was reduced compared to HCM, a close positive correlation was found between the sperm density and the penetration distance (P less than 0.001). The percentage of samples with good HEW penetration increased significantly in parallel with better results of post-coital testing (P less than 0.001). The results indicate that, when fresh human CM is not available, HEW can be used as a medium for the SCPMT as a valuable adjunct to semen analysis which provides information about sperm functional capacity.