Correlation of the hypo‐osmotic swelling test, semen score and the zona‐free hamster egg penetration assay in humans

The correlation between the hypo-osmotic swelling test, the modified Eliasson score for human semen analysis and the hamster egg penetration assay was examined. The results showed a weak but significant correlation between the group of subjects with swelling rates below 50% and the above 80% group. These groups showed hamster egg penetration assay rates of 9 +/- 14% and 39 +/- 29%, respectively (P less than 0.035). A significant correlation was also found between modified Eliasson scores (17 +/- 10 and 5 +/- 7, respectively) and swelling rates below 50% and above 70% (P less than 0.001). These results suggest that spermatozoa showing a low swelling rate have a poor fertilizing capacity. Therefore, the swelling tests and analysis of the patients semen can be used to discriminate sperm quality.