Fertilizing capacity of human spermatozoa evaluated by actual penetration of foreign eggs

Abstract

A system utilizing zona-free hamster oocytes, briefly preincubated, uas used to evaluate the ability for fertilization of human spermatozoa from infertile or normal individuals. Phase-contrast and electron microscopically determined decondensation of the sperm head uas taken as evidence for sperm entry. Forty-one cases were catalogued as fertile (according to the spermiogram) but only 31 (76%) gave a positive sperm entry test. On the other hand, 13 out of 38 (34%) suspected infertile cases also gave a positive test. This bioassay is of potential interest in the investigation and treatment of male infertility as well as for evaluation of the fertilizing ability of human spermatozoa as related to male contraception. © 1978.