Minimal Requirements for Ejaculates Used for in Vitro Fertilization

Abstract

Minimal requirements for ejaculates to be used for in vitro fertilization of human oocytes are defined. Experimental results obtained a total concentration of at least 5 × 10⁶ spermatozoa per ml are required, with at least 30% of the sperm showing normal motility and normal morphology in the differential spermiocytogram. The total volume of ejaculate should not be less than 1 ml. A total of 140 ejaculates from patients taking part in the in vitro fertilization program were examined. In 60 ejaculates (42.9%) bacteria concentrations of greater than 10⁵/ml were found. Eighty (57.1%) of the probes were negative or had bacteria concentrations less than 10⁴/ml. Mycoplasma was found in 30 of the examined ejaculates (21.4%) and the second most frequent group of microorganisms were enterococci found in 15 patients (10.7%). Anaerobic organisms in concentrations of more than 10⁵/ml were not detected. After insemination of one or more pelviscopically obtained oocytes with sperm of the husband in 14 out of 22 cases (63.6%) with bacteria concentrations greater than 10⁵/ml the cleavage of at least one oocyte occurred leading to an embryo-transfer rate of 63.6%. In 14 of 31 ejaculates with negative bacteriological findings (45.2%) at least one of the inseminated oocytes was fertilized. Direct effect of microorganism contaminated sperm on the human in vitro fertilization system resulting in reduced fertilization rates cannot be demonstrated. There is no correlation between microbiological and cytological findings of the ejaculates used for insemination of oocytes and the obtained fertilization rates, cleavage rates, and embryo-transfer rates in the human in vitro fertilization program described here. Since the negative effect on implantation rates or embryonic development cannot be excluded, detailed bacteriological examinations and antibiotic treatments may be recommended before admission to the in vitro fertilization program.