May 21, 2024

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Even mild infection with COVID-19 can lead to long-term decline in the quality and quantity of men’s sperm

Even mild infection with COVID-19 can lead to long-term decline in the quality and quantity of men’s sperm


Even mild infection with COVID-19 can lead to long-term decline in the quality and quantity of men’s sperm.

Since 2023, the number of infections caused by the new coronavirus has been greatly reduced. However, some of the people who recovered from the previous infection will continue to have physical, psychological or cognitive symptoms, that is, Long-COVID sequelae, referred to as “Long-COVID” ( Long Covid ) , affecting about 10% of people infected with COVID-19.


According to the definition of the World Health Organization (WHO) , “long-COVID” is a disease that people infected with the new coronavirus may face. Symptoms usually include fatigue, shortness of breath, dizziness, brain fog, loss of smell or taste, etc. “Long-COVID” can last 3 months, 6 months, 9 months, or even longer, and the disease has been described as the next public health disaster in the making.


More than three months after being mildly infected with the new coronavirus, men still have low sperm concentrations and sperm that are able to swim Also less, although new sperm are constantly being produced during this time.



Even mild infection with COVID-19 can lead to long-term decline in the quality and quantity of men's sperm


Professor Rocio Núñez-Calonge , who led the study , said previous studies had shown that semen quality could be affected in the short term after infection with the new coronavirus, but none had followed men for a longer period of time.

We used to think that semen quality would improve once new sperm were produced, but this is not the case.

We don’t know how long it takes to restore semen quality, and this study shows that even mild infections can cause long-term damage to a man’s sperm quality.


The study previously noted that among some men undergoing assisted reproductive therapy, those who had been infected with COVID-19 had worse semen quality than before infection, even though they had recovered and had a mild infection. Therefore, the research team decided to investigate whether infection with COVID-19 affected sperm quality.


It takes about 78 days for new sperm to be produced, so it is appropriate to evaluate semen quality at least 3 months after infection and recovery from COVID-19.

Between February 2020 and October 2022, the research team recruited 45 men attending six reproductive centers in Spain to participate in the study. All of them were diagnosed with mild COVID-19 infection, and the experimental data came from the analysis of semen samples collected before they were infected.

Another semen sample was collected between 17-516 days after infection. The median age of the men participating in the study was 31 years, and the median time between pre- and post-infection samples was 238 days. The research team analyzed all samples taken within 100 days of infection, and then analyzed a subset of samples taken more than 100 days later.


They found that compared with pre-infection about 100 days after infection and recovery, semen volume dropped from 2.5ml to 2ml (down 20%) , sperm concentration dropped from 68 million/ml to 50 million/ml (down 26.5%) , sperm count dropped from 160 million to 100 million (a drop of 37.5%) , sperm motility (i.e. the ability to move forward and swim) dropped from 49% to 45%, and the proportion of live sperm dropped from 80% to 76%.


These data showed that sperm motility and total sperm count were most affected , with half of the men having a 57% reduction in total sperm count after COVID-19 infection compared with pre-infection levels, but no significant effect on sperm shape.


The research team continued to look at semen samples from men who had recovered more than 100 days from the new coronavirus infection, and the results showed that their sperm concentration and motility still did not improve over time.


The research team believes that the persistent impact on sperm quality after COVID-19 infection may be caused by permanent damage caused by the new coronavirus, even if it is a mild infection. They suggest that clinicians should be aware of the devastating impact of COVID-19 on male fertility.

It is particularly worth noting that this decline in sperm quality occurred in patients with mild symptoms, which means that even though they did not show any clinical symptoms, COVID-19 virus has actually affected their fertility.


We already know that the new coronavirus can infect the testis and the sperm in it, but the mechanism of how it affects sperm is not clear.

This may be related to the inflammation and immune system damage caused by the Long-COVID.

The inflammatory process can destroy germ cells by infiltrating white blood cells involved in the immune system, and reduce androgen levels by affecting androgen-producing interstitial cells.


The research team said it will continue to follow up these participants to detect changes in their semen quality and hormone levels.

They caution that more research should be done on the reproductive function of men infected with the new coronavirus to see whether their fertility is temporarily or permanently affected.


This study highlights the importance of long-term follow-up of people of reproductive age who are infected with COVID-19, even if they are mildly infected. But it’s important to note that the participants in this study still met the World Health Organization’s standards for normal semen and sperm even after their sperm quality and quantity declined. Therefore, it is uncertain whether the decline in their sperm quality and quantity has affected fertility.








Even mild infection with COVID-19 can lead to long-term decline in the quality and quantity of men’s sperm

(source:internet, reference only)

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Important Note: The information provided is for informational purposes only and should not be considered as medical advice.