Introduction

The routine semen analysis is the most important source of information on the fertility status of the male partner. Although gradually being replaced by more sophisticated computer-aided semen analysis methods (CASA; see Chapter 4), most hospital and private laboratories rely on the traditional, manual light microscopic method of assessing semen. Although an important part of the couple-based fertility evaluation, the semen analysis is more an assessment of the potential for fertility, rather than a test of actual fertility. Although only a rough estimate of the functional capability of the spermatozoa, routine semen analysis is an accurate measure of sperm production and epididymal maturation. A definitive diagnosis of male fertility cannot be made as a result of the semen analysis, and thus more sophisticated tests have become useful to the fertility specialist (see Chapters 6 and 9).

Historically, there has been a lack of standardization of methodologies for the semen analysis, as well as difficulty with interpretation of results. This makes comparison of semen analysis results and patient diagnosis nearly impossible between centers. Recently, the World Health Organization has published a manual (now in its third edition) for the laboratory evaluation of semen which encourages the use of standardized procedures for semen analysis (WHO, 1992). This should result in greater comparability among laboratories, as well as improving the precision, reproducibility and interpretation of the results.

This chapter will describe the standard manual methods for performing a semen analysis. Most importantly, however, information useful for the clinical evaluation of infertile couples will be presented, such as when to request a semen analysis, instructions in preparation for the analysis, and the interpretation of results.