Coronavirus may impair sperm quality and reduce fertility in men, according to a new study based on experimental evidence.
The viral disease – which has swept the world, claiming nearly 2.2 million lives – can cause increased sperm cell death, inflammation and so-called oxidative stress, the researchers reported on Friday in the journal Reproduction.
A health professional in Jerusalem testing for coronavirus
(Photo: AFP)
“These findings provide the first direct experimental evidence that the male reproductive system can be affected and damaged by the coronavirus,” concluded the authors.
Experts who commented on the research, however, said the virus’s ability to compromise fertility in men has yet to be proven. Coronavirus causes respiratory diseases, especially in the elderly and latent medical problems.
The world has seen more than 100 million confirmed cases since the disease emerged in central China in late 2019.
Transmitted by respiratory droplets, the disease attacks the lungs, kidneys, intestines and heart.
It can also infect male reproductive organs, impairing the development of sperm and disrupting reproductive hormones, previous studies have shown. The same receptors that the virus uses to access lung tissue are also found in the testicles.
A coronavirus ward at Ziv Medical Center in Safed
(Photo: Aviho Shapira)
But the effects of the virus on men’s reproductive abilities remained unclear.
Behzad Hajizadeh Maleki and Bakhtyar Tartibian of Justus-Liebig-University in Germany researched for biological markers that could indicate a negative impact on fertility.
The analysis done at intervals of 10 days for 60 days in 84 men with coronavirus was compared to data from 105 healthy men.
In patients with COVID-19, sperm showed a significant increase in inflammation and oxidative stress markers, a chemical imbalance that can damage the body’s DNA and proteins.
‘Strong note of caution’
“These effects on sperm cells are associated with poor sperm quality and reduced fertility potential,” said Maleki in a statement. “Although these effects tend to improve over time, they have remained significantly and abnormally greater in patients with coronavirus.”
The more severe the disease, the greater the changes, he added.
The male reproductive system “should be considered a vulnerable route of coronavirus infection and declared a high risk organ by the World Health Organization,” said Maleki.
A coronavirus ward at Sheba Medical Center
(Photo: AFP)
Experts not involved in the study welcomed the research, but warned that more is needed before drawing hard and fast conclusions.
“Men should not be unduly alarmed,” noted Alison Campbell, director of embryology at CARE Fertility Group in Great Britain. “There is currently no definitive evidence of long-term damage caused by the coronavirus, to sperm or to male reproductive potential,” she told the London-based Science Media Center.
The results may have been distorted, she added, because the men who were recovering from Covid were treated with corticosteroids and antiviral therapies, while the control group was not.
A healthcare professional conducting a serological test for antibodies to the coronavirus
(Photo: Avigayil Uzi)
Allan Pacey, a specialist in male reproductive medicine at the University of Sheffield, raised a “strong note of caution” about how the data was interpreted.
Some of the indicators of decreased sperm quality may be due to factors other than COVID-19, he said, noting that more men in the coronavirus group were overweight.
The simple fact that only one group is very ill – no matter what the cause – also needs to be taken into account, he added.
“We already know that a febrile illness can affect sperm production, regardless of what caused it.”