Evaluation of human sperm fertility by interspecific (human spermatozoa-hamster oocytes) in vitro fertilization

Abstract

The fertilizing capacity of 1) Males with unproven fertility to be admitted to an IVF/RE programme; 2) Probably infertile subjects and of 3) Males with idiopathic infertility, has been evaluated using the humster (HUMan-hamSTER) test. Sixty-seven percent of normal sperms from the IVF-Re couples were capable of fertilizing hamster oocytes, with an average fertilization rate of 52%. In one of the suspect male infertility group sperms were able to fertilize hamster oocytes and in the idiopathic infertility group forty-eight percent of sperms fertilize, but the average fertilization rate is clearly lower. It is surprising that 26% of normal sperms have a negative humster test and fertilize the human oocytes at the same rates (86%) as those having a positive humster test. It means that if statistically and over large populations this test undoubtedly gives good results, when the individual cases are taken into consideration this test does not provide final proof of the patient's infertility. Nevertheless the authors stress that the test may provide a new criterion for determining sperm quality and in the future it might become a complementary examination of the spermogram and postcoital test and supply fundamental data on the mechanism of fertilization (capacitation, acrosome reaction, spermatozoa-oocyte fusion and pronuclei formation).