Correlation between semen parameters and the Hamster Egg Penetration Test (HEPT) among fertile and subfertile men in Singapore.

The objective of this retrospective study was to distinguish between fertile and subfertile men based on their semen parameters and hamster egg penetration test (HEPT) outcome. This study involved 110 subfertile men recruited from an infertility clinic and 48 fertile men attending an antenatal clinic in Singapore. The men were required to donate a semen specimen for semen analysis and HEPT assay. The results indicated that the subfertile group had significantly lower normal sperm morphology according to the Tygerberg strict criteria, and lower progressive motility (P < .05). Semen volume, density, HEPT decondensation rate, and sperm penetration index were not significantly different between the 2 groups. Receiver operating characteristic curve analysis indicated that sperm morphology had the highest predictive power of 65.7% with a threshold value of 7%, and progressive motility had a predictive power of 61.8% with a threshold value of 50%. Using the tenth percentile of the fertile population as the cutoff, lower adjusted thresholds of 3% for sperm morphology and 28% for progressive motility were obtained, giving higher positive predictive values of 81.8% and 84.4%, respectively. This study shows that these new cutoff values can be used to screen the general population to identify subfertile men. In contrast, the HEPT proved to be an insensitive and unreliable assay in identifying subfertile males. To our knowledge the comparison of HEPT and semen parameters between subfertile and fertile men has not been previously reported in an Asian population.