Towards Standardization in Reporting Data on Basic Human Semen Examination: A Crucial Step in Advancing the Field of Andrology and Reproductive Medicine

Editorial

Andrology has made substantial advances over the years, contributing not only to improved diagnosis and treatment of infertility, but also to other aspects of reproductive medicine. Sperm evaluation is crucial for assessing male fertility. However, for many years the lack of standardized protocols has hindered the reproducibility and reliability of results between laboratories. To address this pressing issue, it is essential for the field of andrology to prioritize the development and implementation of standardized sperm evaluation protocols.

In this issue of Andrology, five internationally recognized experts in the field of semen analysis, Lars Björndahl, Sandro Esteves, Alberto Ferlin, Niels Jørgensen and Cristian O’Flaherty have contributed a paper entitled “Improving Standard Practices in Studies Using Results from Basic Human Semen Examination”¹ in which they advocate for the implementation of standards for reporting and managing data related to basic human semen parameters. This paper is complemented by a checklist that will soon be mandatory for all authors submitting articles presenting original human semen data to our Journal.

In order to visualize how this step fits in the more general context of evolution of semen analysis, let us shortly summarize some major events in the almost 350 years history of sperm evaluation.

In 1677, the Dutch microscopist and microbiologist Antony van Leeuwenhoek, in a letter addressed to the Royal Society of London, reported the microscopic evaluation findings of Johan Ham, a student from the Medical School of Leyden. In what can be considered as the first report on semen analysis, he described not only the phenomenon of seminal liquefaction, but also the presence, motility patterns, head and tail characteristics of live animalcules that did not survive beyond 24 hours. This finding was subsequently published in the Philosophical Transactions of the Royal Society of London².

Following this groundbreaking discovery it took, however, almost 150 years before Prévost and Dumas³ could show that spermatozoa are not seminal parasites but are needed for the process of fertilization and reproduction. Their report had an enormous impact on the future understanding of the contribution of the male partner on fertility as well as infertility. Furthermore, this report made it clear that access to semen analysis is mandatory for proper investigation of a childless couple.

Development of techniques for routine semen analysis can be dated to the early 20^th century and many consider the study by Macomber and Sanders published in 1929⁴ as starting point of the introduction of semen analysis in clinical and laboratory practice. The two authors introduced the use of a blood counting chamber in assessing sperm concentration. Furthermore, based on investigation of ejaculates from 294 subjects, they established a reference value for sperm count showing that although pregnancy could be achieved with less than 60 x 10⁶/mL, the probability increased with sperm numbers.

Over the next fifty years a growing number of publications reported human semen data analysis. This led the research community to recognize the need for defining standardized, precise, reproducible, sensitive, and validated laboratory procedures for semen analysis⁵. The recognition of such need culminated in the publication in 1980 of the first edition of the “WHO Laboratory Manual for the Examination of Human Semen and Semen-Cervical Mucus Interaction”.⁶ The most recent, sixth edition of this manual, was published in 2021.⁷ Throughout the more than 40 years of this manual’s evolution, not only the rigor in defining methods for basic human semen examination has been significantly strengthened but tools for robust quality control have also been developed. The importance of the WHO manuals for increasing the quality and global harmonization of this analysis can hardly be overstated. The recently published ISO standard (International Standards Organization; ISO 23162:2021 Basic semen examination—Specification and test methods, 2021, ISO, Geneva) is based on the same principles as the sixth edition of the WHO manual, further contributing to a global standardization.

While semen analysis was originally developed for studying male subfertility, it is now also widely applied to monitoring the outcome of male contraceptive efforts, assessing treatments of impaired male fertility, and planning of assisted reproduction. It is also used in epidemiological and other research studies assessing environmental, lifestyle, and occupational exposures potentially hazardous to male reproductive function. Recent data clearly indicate that impaired semen quality may also be a marker of increased risk of common non-contagious diseases⁸. Thus, in the future, examining male semen may not only be relevant for reproductive clinicians and researchers but could be used as a tool in general medical practice. These additional applications not only increase the need for improving the quality of analysis, but also stress the importance of accurate reports of basic semen test results and their statistical handling. As editors of an andrological journal we quite often see the description of method for semen examination condensed to one sentence – “Semen analysis was performed according to the last WHO semen manual edition”. However, a deeper digging into the methodology applied by the authors often reveals major deviations from these guidelines, potentially having significant impact on the quality of the reported data and on their interpretation. Introducing standards for reporting data on basic human semen examination will hopefully be an efficient measure facilitating the development of reliable diagnostic and therapeutic tools and thereby contributing to further progress in the field of andrology.

Hence, the checklist published by Björndahl et al in this issue of Andrology is of outmost importance for raising the quality of publications that contain original basic semen analysis data. Therefore, Andrology will require a completed checklist in connection with all future submissions of manuscripts featuring this type of data. Any deviations from the WHO and ISO recommendations must be documented and their impact on the analysis outcomes will need to be reported and validated.

At the same time, we also understand that like any other similar document, this checklist also needs to be tested and, if necessary, refined. We therefore hope that our authors, reviewers and associate editors, will be willing to provide us constructive feedback that can contribute to further improving this tool.

Standardization of not only the analytical methods but also reporting of semen evaluation data is an urgent and crucial step in advancing the field of andrology. As one of the leading journals in the field of male reproductive function, Andrology will also take a leading role in introducing standard routines for reporting this type of data. At the same time, we would like to encourage other journals in the field of reproduction to follow our example. This will largely benefit global exchange and utilization of available human data and thereby contribute to our understanding and management of disorders related to male fertility. It is time for the scientific community to unite, prioritize standardization, and thereby pave the way for a brighter future in andrology.