WHO 2021 and 2030 reference values for semen assessment: three challenges for andrology in the journey ahead

Vasconcelos, Ana Luísa; Henedi, Zeina; Barratt, Christopher L.R.

doi:10.1016/j.rbmo.2022.03.027

Cited by 6 publications

(5 citation statements)

References 23 publications

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“…Support for our observations comes from previous contributions which have elegantly identified key issues related to WHO reference values for semen assessment and the main sources of variability among studies such as the quality of sample examination, the paucity of high-quality data collection from primary studies or the poor geographical spread ( Campbell et al , 2021 ; Vasconcelos et al , 2022 ).…”

Section: Discussionsupporting

confidence: 75%

“…Given the limited value of the reference values obtained to date, suggestions to overcome the problem in the future are of utmost importance ( Vasconcelos et al , 2022 ). The great heterogeneity among the studies can be attributed to the specific problems related to the composition and handling of human semen ( Björndahl, 2022 ) or to the plethora of standard operating procedures available, some of which are still not validated for clinical practise, such as the computer-assisted sperm analysis ( Tang et al , 2015 ).…”

Section: Discussionmentioning

confidence: 99%

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The statistical foundation of the reference population for semen analysis included in the sixth edition of the WHO manual: a critical reappraisal of the evidence

et al. 2022

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In the most recent version of the ‘WHO Laboratory Manual For The Examination And Processing Of Human Semen’, the updated target population used to infer reference values included 3589 fertile subjects, representative of 12 countries and 5 continents, and 10 studies. We have critically evaluated the newly proposed distribution of semen examination results using an approach borrowed from clinical chemistry laboratories and based on the recommendations of the International Federation of Clinical Chemistry for estimation of reference intervals. Surprisingly, most prerequisites to produce common reference intervals through multicentric data were not met. Moreover, when we assessed with the bootstrap method the descriptive reference values obtained from raw data of the 10 individual studies for sperm concentration, sperm number, motility and normal forms, we found that none of the populations was completely correctly described by the reference centiles. We concluded that aggregated data used to build the reference distribution cannot be considered to originate from the same population, and this can result from real differences among individuals or different methodological approaches used in the various studies. Transferability conditions across studies did not seem to have been met. Our findings strengthen the relevance of concerns regarding the use of reference populations in the World Health Organization manual to discriminate between fertile and infertile men.

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Section: Discussionsupporting

confidence: 75%

Section: Discussionmentioning

confidence: 99%

The statistical foundation of the reference population for semen analysis included in the sixth edition of the WHO manual: a critical reappraisal of the evidence

et al. 2022

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“…There are many other ways that we can encourage authors to be more transparent with their technical methods (see Vasconcelos et al , 2022 ). Several foundations (i.e.…”

Section: Discussionmentioning

confidence: 99%

“…ESHRE, American Society for Reproductive Medicine, European Academy of Andrology and The International Society of Andrology) to consider adopting these, or similar ideas, as this will help foster confidence in existing published data. Another way to increase standardization would be through international collaborative networks and the creation of video tutorials and/or training materials to walk through the protocols for each semen characteristic ( Vasconcelos et al , 2022 ). These could be embedded in social media platforms to normalize semen analysis and make information more accessible and the methods easier to follow.…”

Section: Discussionmentioning

confidence: 99%

Do studies published in two leading reproduction journals between 2011 and 2020 demonstrate that they followed WHO5 recommendations for basic semen analysis?

et al. 2022

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STUDY QUESTION Do publications that involve the interpretation of the results of a basic semen analysis, published in Human Reproduction and Fertility & Sterility between 2011 and 2020, give sufficient evidence in their methodology to demonstrate that they followed the technical methods recommended in the fifth edition of the World Health Organization (WHO) laboratory manual, entitled WHO Laboratory Manual for the Examination and Processing of Human Semen (WHO5)? SUMMARY ANSWER Evidence of methodological agreement of studies with the WHO5 recommendations was low, despite 70% of papers stating that they followed WHO5 recommendations. WHAT IS KNOWN ALREADY A basic semen analysis is currently an integral part of infertility investigations of the male, but method standardization in laboratories remains an issue. The different editions of the WHO manual for the basic semen analysis (WHO1–6) have attempted to address this by providing increasingly rigorous methodological protocols to reduce experimental error. However, to what extent these methods are followed by studies that involve the interpretation of the results of basic semen analysis remains unknown. STUDY DESIGN, SIZE, DURATION A survey of the technical methods used to perform a basic semen analysis was conducted on studies published in two leading reproduction journals (Human Reproduction and Fertility & Sterility) between 2011 and 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS The literature search was performed on the electronic databases PUBMED and MEDLINE Ovid between January 2021 and March 2021. The MeSH terms included in the search were ‘sperm concentration’ OR ‘sperm motility’ OR ‘sperm morphology’ OR ‘sperm vitality’ OR ‘male fertility’ AND ‘human spermatozoa’ NOT ‘animals’. A total of 122 studies were available for analysis. MAIN RESULTS AND THE ROLE OF CHANCE In total, 70% of the studies cited WHO5 in their methods section. Of the remaining studies, 10% cited the fourth edition of the WHO laboratory manual (WHO4), 7% cited both WHO4 and WHO5, 1% cited the third edition of the WHO laboratory manual (WHO3), and 12% did not cite the WHO at all. Overall methodological agreement with WHO5 recommendations was poor, with the main reason for this lack of agreement being that the research studies did not disclose specific details of the technical methods and equipment used. LIMITATIONS, REASONS FOR CAUTION In the case of studies that did not disclose any specific technical methods that they used, we did not attempt to contact these authors and so were unable to confirm the agreement between their technical methods and WHO5 recommendations. WIDER IMPLICATIONS OF THE FINDINGS Our findings suggest there is an urgent need to develop strategies to address standardization in reporting the results of a semen analysis for publication. This is particularly timely given the recent publication of WHO6 and ISO standard 23162 for the basic examination of human semen. STUDY FUNDING/COMPETING INTEREST(S) There was no funding for this project. C.L.R.B., as an employee of the University of Dundee, serves on the Scientific Advisory board of ExSeed Health (from October 2021, financial compensation to the University of Dundee) and is a scientific consultant for Exscientia (from September 2021, financial compensation to the University of Dundee). C.L.R.B. has previously received a fee from Cooper Surgical for lectures on scientific research methods outside the submitted work (2020) and Ferring for a lecture on male reproductive health (2021). C.L.R.B. is Editor for RBMO. TRIAL REGISTRATION NUMBER N/A.

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“…The prevalence of infertility appears to be increasing. As well as the obvious contributions from increasing maternal age with delayed reproduction, environmental risks and general health impacts, 6,7 it is likely there is less reticence for seeking help and greater awareness of the availability of effective assistance. 8…”

Section: Defining the Problem And Its Prevalence: Is Infertility Actu...mentioning

confidence: 99%

An update on fertility assistance and assisted reproductive technologies

Rozen¹,

Stern²

2023

Aust J Gen Pract

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WHO 2021 and 2030 reference values for semen assessment: three challenges for andrology in the journey ahead

Cited by 6 publications

References 23 publications

The statistical foundation of the reference population for semen analysis included in the sixth edition of the WHO manual: a critical reappraisal of the evidence

The statistical foundation of the reference population for semen analysis included in the sixth edition of the WHO manual: a critical reappraisal of the evidence

Do studies published in two leading reproduction journals between 2011 and 2020 demonstrate that they followed WHO5 recommendations for basic semen analysis?

An update on fertility assistance and assisted reproductive technologies

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