Changes in sperm motility, morphology and concentration induced by the swim-up procedure.

Fifteen semen samples from normal donors were washed twice in Earle's medium by centrifugation and allowed to swim up into overlayered Earle's medium. Aliquots of 0.2 ml were drawn before and after the swim-up, for assessment of sperm motility, morphology and concentration. The percentage of sperm showing progressive motility improved by an average of 54.02 +/- 45.97%, and sperm with the normal morphology increased by 63.8 +/- 31.01%. Head and tail abnormalities decreased by 47.17 +/- 21.3% and 89.37 +/- 16.1% respectively. There was no statistical change in acrosomal abnormalities. Sperm concentration was reduced by 89.02 +/- 7.4%. It is concluded that the standard swim-up technique resulted in an overall improvement in sperm quality, but that the technique was not effective in reducing the acrosomal abnormalities.