Abstract: It is possible and clinically relevant to distinguish between slow and rapid progressive spermatozoa in basic semen analysis. This is discussed in light of the different purposes of semen analysis for the subfertile couple and the male patient. The two groups of progressive spermatozoa should be distinguished
to help ensure that pertinent information available in the semen sample is not neglected.

Key words: Male factor infertility, Manual sperm motility assessment, Quality control, Rapidlyprogressive spermatozoa, Reference values, Semen analysis, Staff training