Originally thought to have a profound effect on the respiratory system, researchers now know that Covid-19 symptoms are numerous and varied.
Adverse cases of Covid-19 can affect a person’s sperm quality, and thus potentially affect his or her fertility, according to a new study published Thursday in the journal Reproduction.
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“These findings provide the first direct experimental evidence that the male reproductive system could be targeted and damaged by Covid-19,” the authors concluded.
Experts citing the research, however, said the virus’ ability to damage fertility in men remains unproven.
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Covid-19 causes respiratory illness, especially in the elderly and those with underlying medical problems.
The world has seen more than 100 million confirmed cases since the outbreak in central China in late 2019.
Passed through respiratory droplets, the disease attacks the lungs, kidneys, intestines and heart.
It can also infect male reproductive organs, adversely affecting sperm cell development and disrupting reproductive hormones, previous studies have shown. The same receptors that the virus uses to get to the lungs are found in the testicles.
But the effect of the virus on male reproductive capacity was not yet clear.
Behzad Hajizadeh Maleki and Bakhtyar Tartibian from the University of Justus-Liebig in Germany were looking for biological markers that may indicate adverse effects on fertility.
Analysis was performed at 10-day intervals for 60 days in 84 men with Covid-19 compared with data for 105 healthy men.
In the Covid-19 patients, sperm cells showed a significant increase in signs of inflammation and oxidative stress, a chemical imbalance that can damage DNA and proteins in the body.
‘Strong note of warning’
“These effects on sperm cells are associated with lower sperm quality and lower fertility potential,” Maleki said in a statement.
“While these effects tended to worsen over time, they remained significantly and significantly higher in Covid-19 patients.”
The worse the disease, the greater the changes, he said.
The male reproductive system “should be considered a vulnerable strain of Covid-19 disease and be declared a high-risk organ by the World Health Organization,” Maleki said.
Experts not involved in the study welcomed the research but warned that more was needed before making hard and swift decisions.
“Men shouldn’t be too scared,” said Alison Campbell, CARE Product Group ‘s director of pioneering in Britain.
“There is currently no conclusive evidence of long-term damage caused by Covid-19, to sperm or male reproductive capacity,” she told the London-based Science Media Center.
The results could be slowed, she said, because men who overdosed on Covid were treated with corticosteroids and antiviral medications, while the control group did not.
Allan Pacey, an expert in male reproductive medicine at the University of Sheffield, issued a “hard warning note” on how the data was interpreted.
Some of the signs of reduced sperm quality may be due to factors in addition to Covid-19, he said, noting that more men in the Covid-19 group were obese.
Attention must be paid to the simple fact that only one group was seriously ill – for whatever reason – he said.
“We already know that febrile illness can affect sperm production, whatever the cause.”
(Supported by organizations)