Quality control during the conventional analysis of semen, an essential exercise.

Intra- and inter-technician variability in assessing sperm motility by the methods recently advocated by the World Health Organization (WHO) were studied. The intra- and inter-technician variability in estimating sperm concentration and the intra-technician variability in assessing sperm morphology were also examined. Intra-technician variability in assessing sperm motility appeared to be related to the natural ability and/or training of the observer. Although in general the intra-technician variability was low, there were marked and clinically significant differences between observers when assessing the same semen sample. There was no significant difference between observers in the assessment of sperm concentration, and intra-technician variability was low. When assessing sperm morphology, the intra-technician variability was potentially large (above a level of 20% morphologically ideal spermatozoa). Technicians should be recruited who have natural ability as observers. Quality control appears to be an essential exercise for any center that plans to relate semen parameters to fertility outcome.