Swim-over: an alternative method for harvesting motile spermatozoa.

An alternative method for harvesting motile spermatozoa has been developed. Two plastic chambers, one with human semen and one with Earle's medium, were connected by a glass tube filled with cervical mucus. Semen samples were obtained from 18 men. Mid-cycle, sperm-free cervical mucus was provided by 18 women. During incubation aliquots were drawn from the culture chamber every hour for analysis of sperm characteristics. A pronounced increase in motility was observed. The number of penetrated sperms averaged 1 million after 3 hr. The percentage normal morphology increased from 42 +/- 11 to 73 +/- 15 (mean +/- SD). It is suggested that "swim-over" should prove useful for obtaining sperm of high quality. Further studies for refinement and evolution of the method are currently in progress.