The importance of sperm motility for the fertilization of human oocytes in vivo and in vitro.

Motility behaviour of spermatozoa in 289 ejaculates was investigated by laser-Doppler-spectroscopy in the andrology-laboratory of the University Hospital for Gynecology and Obstetrics, Graz/Austria. Conventional spermiograms, performed on the same ejaculates, permitted comparisons between estimated motility and laser-measurements, comprising the following parameters: Total sperm motility, mean sperm velocity, percentages of progressive motile spermatozoa and mean progressive velocity. In order to elucidate the importance of sperm motility for the fertilization of oocytes in vivo and in vitro, ejaculates of six different groups of patients were evaluated. In vivo: 173 patients from the andrologic outpatient service (group A); 38 patients from the andrologic outpatient service, whose wives became pregnant (group B) and 20 donors with recently proved fertility (group C). In vitro: 8 patients, whose ejaculates failed to fertilize the oocytes (group D); 39 patients with successful fertilization (group E) and 12 patients with ongoing, clinical pregnancy of their wives after ivF (group F). In addition, motility behaviour was assessed in native ejaculates 24 hours after ejaculation, as well as changes in sperm motility after capacitation. Statistical evaluations of group comparisons revealed a good correlation between estimated results and laser measurements. Mean sperm velocity and progressive sperm motility are the most selective parameters within the group differences in oligozoospermic ejaculates. Besides motility, morphology is of importance in vivo as well as in vitro. Based on the results of measurements obtained in the different groups, the following guidelines for standard values in laser-Doppler-spectroscopy are proposed: Total sperm motility greater than 53%; mean sperm velocity greater than 42 microns/sec.; progressive sperm motility greater than 34% and mean progressive velocity greater than 68 micron/sec. If these values are not reached, medical treatment is recommended.