O-016 Sperm motility has declined between 2017 and 2022 among candidate sperm donors in Denmark
Notice bibliographique
Résumé
Abstract Study question Has sperm quality among candidate sperm donors in Denmark changed in recent years (2017-2022)? Summary answer Although sperm concentration of candidate donors did not change, sperm quality (motility) declined by ∼35% after controlling for age and other potential confounds. What is known already Questions remain about whether human sperm quality has declined in recent decades. Whilst some studies support this trend, others dispute it due to potential biases in the populations studied or the different methodological approaches to measuring sperm quality. Resolution of this issue is important because of the implications for human fertility, as well as for those involved in the recruitment of donors for use in Medically Assisted Reproduction. Study design, size, duration We analyzed the semen quality of 6,774 candidate sperm donors attending for their first semen analysis at Cryos International from 2017 to 2022 at four cities in Denmark: Aarhus, Aalborg, Copenhagen, and Odense. We analyzed only the first sperm sample, whether or not the candidate was eventually accepted as a donor. All donor candidates were between 18 and 46 years old and lived in or near these four cities. Participants/materials, setting, methods Ejaculates were examined within one hour of production. Semen volume (mL) was estimated by weight and both total sperm concentration (106/mL) and the concentration of grade A and B spermatozoa were measured using the same protocols and CASA-system across all years at each site. Analyses were controlled for age, site, ejaculate volume, and the average monthly temperature when the ejaculate was produced. We used longitudinal data from accepted donors to test for methodological biases. Main results and the role of chance From 2017 to 2022, there was no evidence of changes in either semen volume (median = 3.5 mL) or sperm concentration (median = 58 million/mL) in the ejaculates of candidate donors. There was, however, clear evidence of a decline in the concentration (and total number) of grade A and B motile sperm. For the average candidate sperm donor that we studied, the concentration of grade A sperm declined from 5.15 [95% CL: 4.18, 6.34] million/mL in 2018 to 3.33 [2.71, 4.08] million/mL in 2022. This corresponds, for example, to a predicted decline in sperm quality of ∼35% for a 25-year-old candidate from Aarhus in a month when the average daily high temperature was 18.5 °C. The same pattern was evident from all four cities, but candidates at Aarhus had lower overall sperm quality (grade A sperm motility) than candidates at the other three cities. Analysis of the longitudinal data from repeated donations from all 'accepted' donors during this same period (2017 – 2022), allowed us to rule out methodological factors (sperm collection, CASA, statistical anomalies) that might have influenced these findings. Limitations, reasons for caution We cannot rule out the possibility that men with poor sperm quality were more likely to apply to be donors during the global pandemic, or that the lifestyles of candidate donors had changed during this period because of lockdowns or changes in work patterns. Wider implications of the findings Candidate sperm donors are a useful population in which to monitor changes in human semen quality over time. The results may have implications for human fertility and the recruitment of sperm donors, where motile sperm concentration is an essential selection criterion. Trial registration number not applicable
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Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».