Effect of antisperm antibodies in serum and cervical mucus on the capacity of human sperm to penetrate zona-free hamster ova.

Human sera with elevated titers of antisperm antibodies reduced the capacity of human sperm to penetrate zona-free hamster ova. Of 111 sera examined, 33 (30%) reduced the mean percentage of ova penetrated to less than 52%, which was significantly different from the overall control mean (75%). Three sera reduced the penetration of ova to 7% or less. The inhibitory effect of these three sera was still present in their respective Fab preparations. An analysis of antibody effects revealed that the presence of sperm-immobilizing antibodies had a significantly greater influence on sperm penetration capacity than agglutinating antibodies. Sperm motility per se appeared to be unaffected by the different sera. Sperm treated with cervical mucus (CM) samples generally exhibited a lesser degree of ova penetration than did sperm treated with serum or medium alone. Among CM groups, however, samples containing detectable sperm-immobilizing antibody activity or samples from women with circulating antisperm antibody caused significant reductions in sperm penetration capacity.