SEMEN ANALYSIS PERFORMED BY DIFFERENT LABORATORY TEAMS - AN INTERVARIATION STUDY

Some recent studies have indicated that sperm concentration has decrea sed during the last 50 years. However, comparisons between laboratorie s have revealed that geographical differences seem to exist and that a ny decrease may not be global. One point of criticism concerning compa rison of results from different laboratories has been that some of the discrepancies detected could reflect the lack of standardized methods used in the different laboratories. Four teams, each consisting of on e physician and one technician from groups which have recently publish ed data on semen quality, met in order to evaluate the variability bet ween their laboratories on semen analysis. Twenty-six fresh semen samp les from unselected men were analysed. The groups analysed the samples according to the normal practice in their laboratories, using their o wn equipment. The variation between laboratories was estimated through a random effects model. For sperm concentration and semen volume asse ssment a remarkable consistency between laboratories was detected, in contrast to the very considerable interindividual variation. For sperm motility and morphology assessments interlaboratory consistency was m uch poorer. In conclusion, evaluation of sperm motility and morphology characteristics requires further standardization in order to achieve comparable data from different laboratories. However, semen volume and sperm concentration are characteristics which can be compared reliabl y between laboratories, when similar methodologies are used.