The relationship between the human spermatozoa hypo-osmotic swelling test and the human spermatozoa zona-free hamster ova penetration bioassay

Abstract

General semen analysis alone cannot ascertain spermatozoal fertilizing ability which is commonly determined by the human sperm zona-free hamster ova penetration assay. This is expensive and time-consuming and thus an alternative test for male fertility is desirable. Jeyendran et al. recently reported a significant correlation between the swelling of fertile human sperm exposed to hypo-osmotic shock and fertilization of zona-free hamster ova. It is assumed that human sperm hypo-osmotic swelling reflects functional integrity of the sperm membrane, which may also be a test for spermatozoal fertilizing ability. In the present study, 148 semen samples from the husbands of infertile couples were subjected to general semen analysis, the hypo-osmotic swelling test and the hamster ova assay. No significant correlation was found between spermatozoal swelling and zona-free hamster egg penetration, from which we conclude that the two tests are apparently evaluating non-associated functional qualities of spermatozoa.