The WHO laboratory manual for the examination and processing of human semen (originally WHO laboratory manual for the examination of human semen and sperm–cervical mucus interaction) was first published in 1980, in response to a growing need for standardization of procedures for the examination of human semen. The manual was revised four times (Belsey, et al., 1980, World Health Organization, 1987, World Health Organization, 1992, World Health Organization, 1999, World Health Organization, 2010), widely read and translated into a number of languages. Indeed, over the past thirty years, the manual became a recognized standard and used extensively by clinical and research laboratories throughout the world. It is a procedural manual not only for those new to semen analysis, but a reference for all who process and examine semen to define its parameters for clinical practice or clinical and epidemiological research studies.
Over the past ten years many new tests and techniques were validated and made available for clinical and research purposes. Prompted by these considerations, WHO established an Editorial Board (EB) to review all the methods described in the 5th Edition of the Manual, with a view to endorsing, changing, or updating them.