The results of a new study challenge recent reports that men's sperm counts are declining globally.
Using data from 6,758 men from four cities in Denmark aged between 18 and 45, who applied to donate sperm at the world's largest sperm bank, Cryos International, where samples were analyzed within an hour of donation using computer systems, the researchers found Average sperm concentration (number of sperm per milliliter of semen) did not change dramatically between 2017 and 2022. However, they noticed a decline in numbers of high-quality 'swimming' sperm starting around 2020, when lockdowns had an impact on men's diet and physical activity.
Professor Alan Pacey, author of the study from the University of Manchester, said: Low sperm motility, where sperm are unable to swim efficiently, can be easily treated with a healthy lifestyle. But he stressed that the results showed no evidence of a decrease in sperm count in general. He added that society's focus on sperm count is wrong, because the focus should instead be on the quality of the man's sperm.
Professor Pacey noted that the widely held view on low sperm counts comes from research published last year which suggested concentrations had fallen by about 2.64% per year since 2000.
Professor Pacey continued: "It is common that men's sperm count decreases. But we did not see a change in sperm concentration in our research, so we do not support this idea. We hope this will make some people feel good."
The team found that from 2017 to 2019, semen volume, sperm concentrations, and total sperm counts in donor samples increased by 2-12%. Then, from 2019 to 2022, the concentration of swimming sperm submitted for testing decreased by 16%, while the total number of swimming sperm decreased by 22%, which "roughly corresponds to the onset of the worldwide COVID-19 pandemic."
Professor Robert Montgomery, co-author of the study, from Queen's University in Canada, said that although the decrease in swimming sperm numbers was an "unexpected finding", there was no evidence to suggest that Covid-19 was directly affecting the virus. On sperm.
He explained: “Although there is no evidence to suggest that the SARS-CoV-2 virus directly affects sperm, we suggest that widespread lockdowns may have led to changes in work patterns, diet and levels of physical activity that we already know can Affects sperm motility.
Professor Bassi noted that monitoring the quality of semen in a group of sperm donors over time could provide more in-depth answers, so he will continue his research.
Commenting on the research, Chris Barratt, Professor of Reproductive Medicine at the University of Dundee, said: “Studies to date have not investigated sperm motility well, but this study has done a good job. These data are important because they show, on a large sample screened with high-quality methods, that we "We should focus on sperm quality, rather than sperm quantity."
The results were published in the journal Human Reproduction.