Although sperm morphology evaluation is one of the most important aspects of the semen analysis if done correctly and accurately, a trend is developing in which many laboratories or clinicians no longer regard sperm morphology as relevant due to the very low normal reference value of only 4% morphological normal spermatozoa given in the newest (2010) WHO-5 semen analysis manual. However, to maintain its relevance, sperm morphology evaluation, like the rest of the standard semen analysis, should be performed according to well-defined procedures. If performed correctly and according to high standards, morphology data are of high predictive value for male fertility potential and are critical in selecting the assisted reproductive techniques (ART) treatment. With the new low normal value it is becoming even more important that not only percentage normal and abnormal be reported but also that an in-depth report be given on the types of abnormalities present which will be important in selecting the type of clinical procedure to be adopted in ART, being, IUI, IVF, or ICSI. The methods to properly evaluate human sperm morphology are described in this chapter.
