The frequency of Y chromatin-positive spermatozoa during in vitro penetration tests under various experimental conditions.

Complete analysis were carried out on the semen of 55 subjects. The semen was then investigated by using the fluorescent microscopic technique to determine the percentage proportion of Y chromatin-bearing spermatozoa. After staining with quinacrine mustard, an average Y chromatin frequency of 48.2% +/- 2.9% was recorded. With this spermatozoal material, 139 in vitro penetration tests were carried out with cervical mucus. After penetration there was a small, but statistically significant, increase in the percentage of Y spermatozoa (to 52.7% +/- 3.8%). The figures thus recorded were then correlated under variable experimental conditions in addition to variable semen parameters. The ratio of X:Y spermatozoa was related to the duration of the penetration tests, varying temperatures during the penetration, varying acid values of semen and cervical secretion, and also to the value of sperm motility in the semen analysis and to cervical factors. None of the above variables had any measurable influence on the percentage distribution of X and Y spermatozoa during in vitro penetration.