The new, sixth edition of the WHO recommendation from 2021 on semen examination – what changes and novelties for the seminology laboratories?

Semen examination is the first step of diagnosis of a man from an infertile couple. The obtained result directs further diagnostic work-up in order to clarify the causes of the couple’s infertility and to implement treatment. The manuals of the World Health Organization, which have been published for over 40 years, are the basis for the standardization of procedures performed during examination and the reference values used in seminology laboratories all around the world. In 2021, 11 years after the last edition, the latest 6th edition of this manual was published. The following article presents the most significant changes to the basic semen examination procedures compared to the previous guidelines from 2010. Additional seminological tests, which have been included in two separate chapters, as an extended or advanced evaluation of semen, sperm function and quality, are also presented. Recommendations and changes regarding the interpretation of the semen examination result using the so-called “reference values” are discussed.