WHO manual...who should care?

Improving standard practices in studies using results from basic human semen examination

The purpose of this article is to provide an explanation of the background behind a checklist that declares the laboratory methods used in a scientific study. It focuses primarily on implementing laboratory procedures to yield reliable results in basic semen examinations. While the World Health Organization (WHO) and international standards provide recommendations for basic semen examination, manuscripts submitted to Andrology frequently lack transparency regarding the specific techniques used. In addition, the terminology used for semen examination results often fails to provide a clear definition of the groups under study. Furthermore, the WHO's reference limits are often misinterpreted as strict boundaries between fertility and infertility. It is important to note that valid clinical andrological diagnoses and treatments cannot rely solely on semen examination results; they require proper laboratory procedures as a foundation for diagnosing and treating male patients. Therefore, scientific journals should promote the adoption of robust laboratory practices and an accurate definition of patient groups. A checklist can facilitate the design of high-quality studies and the creation of informative publications. Further, it can help journals assess submitted manuscripts and improve the overall quality of their publications.

Evolution of the WHO "Semen" processing manual from the first (1980) to the sixth edition (2021)

As stated clearly in all editions of the WHO Laboratory Manual for the Examination and Processing of Human Semen, the goal of the manual is to meet the growing needs for the standardization of semen analysis procedures. With constant advances in andrology and reproductive medicine and the advent of sophisticated assisted reproductive technologies for the treatment of infertility, the manual has been continuously updated to meet the need for new, evidence-based, validated tests to not only measure semen and sperm variables but also to provide a functional assessment of spermatozoa. The sixth edition of the WHO manual, launched in 2021, can be freely downloaded from the WHO website, with the hope of gaining wide acceptance and utilization as the essential source of the latest, evidence-based information for laboratory procedures required for the assessment of male reproductive function and health.

The sixth edition of the WHO manual on semen examination: ensuring quality and standardization in basic examination of human ejaculates

A basic semen investigation has established principles that are necessary for ascertaining reliable and internationally comparable results. Although these principles have been present in the WHO manual since its inception, the baseline issue across most published studies and practice in reproductive medicine (in which the male is considered) is repetitive failure to adhere to these principles, thereby leading to relevant comparable data and accuracy. To address this failure, the sixth edition of the WHO manual includes revised basic methods, and a complementary formal standard of the International Standards Organization (ISO23162:2021) for basic semen examination has been published. Perhaps the most significant change in the sixth edition is the reintroduction of the four-category distinction of sperm motility, which causes additional work for laboratories in changing reporting parameters but is clinically important. Another essential change is the widened focus from mainly a prognostic tool for medically assisted reproduction to additionally raising awareness of semen examination as a measure of male reproductive functions and general male health.

Current updates on laboratory techniques for the diagnosis of male reproductive failure

The incidence of male reproductive failure leading to infertility, whether due to delayed parenthood, environmental issues, genetic factors, drugs, etc., is increasing throughout the world. The diagnosis and prognosis of male subfertility have become a challenge. While the basic semen assessment has been performed for many years, a number of studies question the value of the traditional semen characteristics. This is partly due to inadequate methods and standardization, limited knowledge of technical requirements for quality assurance, and an incomplete understanding of what clinical information a semen assessment can provide. Laboratories currently performing semen and endocrine assessment show great variability. The World Health Organization (WHO) manual for the evaluation of semen has been the core of andrology and fertility evaluation that has helped in further development of this field over many years. These include the physical appearance of the ejaculate, assessments of sperm count, motility, vitality, morphology, and functional aspects of the sperm and semen sample. These tests also include male endocrine profile, biochemical evaluation of the semen, detection of antisperm antibodies in serum, the use of computer-aided sperm analysis (CASA), sperm DNA integrity, and its damage due to oxidative stress. Assisted reproductive techniques (e.g., IVF, ICSI) have shown great success but are too expensive. Further development in this field with newer techniques and extensive training/instructions can improve accuracy and reduce variability, thus maintaining the quality and standards of such an evaluation. There is an urgent need to have standardized training centers and increased awareness in this area of men's health for reproductive success.

Diagnostic tools in male infertility-the question of sperm dysfunction

Sperm dysfunction is the single most common cause of infertility, yet what is remarkable is that, there is no drug a man can take or add to his spermatozoa in vitro to improve fertility. One reason for the lack of progress in this area is that our understanding of the cellular and molecular workings of the mature spermatazoon is limited. However, over the last few years there has been considerable progress in our knowledge base and in addressing new methods to diagnose sperm dysfunction. We review the current state of the field and provide insights for further development. We conclude that: (i) there is little to be gained from more studies identifying/categorizing various populations of men using a basic semen assessment, where an effort is required in making sure the analysis is performed in an appropriate high quality way; (ii) technological development is likely to bring the reality of sperm function testing closer to implementation into the clinical pathways. In doing this, these assays must be robust, cheap (or more appropriately termed cost effective), easy to use and clinically useful; and (iii) clinical necessity, e.g., the need to identify the highest quality spermatozoon for injection is driving basic research forward. This is an exciting time to be an andrologist and, likely, a fruitful one.

“Oligozoospermia,” “azoospermia,” and other semen-analysis terminology: the need for better science

The Greek-based terms used to describe semen-analysis abnormalities (e.g., "oligozoospermia" and "azoospermia") are unscientific, have overlapping definitions, and are often misinterpreted. The best course is to abandon these vague and difficult labels and simply report semen analyses quantitatively.