[The importance of sperm quality for in vitro fertilization--results of studies in human systems and zona pellucida-free hamster cell system].

In this report the minimum requirements for ejaculates to be used for in vitro fertilization of human oocytes are defined. Based on the experimental results obtained a total concentration of at least 5 X 10(6) spermatozoa per ml are required, with at least 30% of the sperm showing normal motility and normal morphology in the differential spermio-cytogram. The total volume of the ejaculate should not be less than 1 ml. Samples for insemination of human oocytes must be proven to be free of pathological microorganisms. In more than 40% of the cases examined bacteria concentrations of more than 10(5)/ml were detected during routine bacteriological check-ups. Especially enterococci und mycoplasma were frequently found. To further establish the quality of human spermatozoa, 91 ejaculate probes were tested within the hamster system using zona-free oocytes. A statistically significant correlation between sperm quality and the penetration rates of human spermatozoa into zona-free hamster oocytes was shown. A positive effect on penetration rates was observed after addition of L-ascorbic acid and Douglas-aspirate to the incubation medium. Rates increased 12 and 17%, respectively. Addition of kallikrein showed no effect on the penetration rates. Application of ejaculates with high concentrations of leucocytes for insemination of hamster oocytes resulted in clearly reduced penetration rates. Leucocyte concentrations of more than 10% led to penetration rates of 0%. The same reduction was observed when ejaculates with high concentrations of pathological micro-organisms (more than 10(5)/ml) were tested. After addition of sperm antibody containing sera from female sterility patients to the incubation medium also clear reduction of penetration rates was evident depending on: the antibody concentration, the initial motility of the spermatozoa used, and on the level of the primary penetration rate obtained without addition of antiserum.