A critical look at semen analysis

In this article, human semen analysis is examined critically and some of the difficulties it presents in terms of interpretation are highlighted. The problem of defining fertility is raised and a brief comparison is made between farm animals and humans. The purpose of analysis in each differs markedly, yet conventional tests on human semen are derived from semen analysis in animals. Sperm count, sperm motility and sperm morphology are considered and the point is made that in attempts to predict the fertilizing capacity of a semen sample, measurement of the volume of the semen is unhelpful. It is also stressed that several different tests must be applied for a meaningful report to be produced. It is suggested that different boundaries from those applied in animals are required in humans. This is because there is much greater variation in the quality of human semen than in that of animals and, therefore, in trying to establish a norm, a broader framework is required. Finally, it is proposed that fundamental research into the physiology of human spermatozoa is necessary to achieve better standards in semen testing in the future.