Coronavirus may affect sperm quality and decrease fertility in men, according to a new study based on experimental evidence.
The viral disease – which has taken over the world and claims nearly 2.2 million lives – can lead to increased sperm death, inflammation and so-called oxidative stress, researchers reported Friday in the Reproduction journal.
A health worker in Jerusalem conducting tests for coronavirus
(Photo: AFP)
“These findings are the first direct experimental evidence that the male reproductive system may be targeted and damaged by coronavirus,” the authors concluded.
However, experts commenting on the study said the virus’s ability to compromise fertility in men is unproven. Coronavirus causes respiratory illnesses, especially in the elderly and those with underlying 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 drops, the disease affects the lungs, kidneys, intestines and heart.
It can also infect male reproductive organs, disrupt sperm development and disrupt 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 department at the Ziv Medical Center in Safed
(Photo: Aviho Shapira)
But the virus’s effects on men’s ability to reproduce remained unclear.
Behzad Hajizadeh Maleki and Bakhtyar Tartibian from Justus-Liebig University in Germany searched for biological markers that may indicate a negative influence on fertility.
Analysis performed at 10 day intervals for 60 days in 84 men with coronavirus was compared with data from 105 healthy men.
In the COVID-19 patients, sperm cells showed a significant increase in markers of inflammation and oxidative stress, a chemical imbalance that can damage the DNA and proteins in the body.
‘Strong warning’
“These effects on sperm are associated with lower sperm quality and reduced fertility potential,” Maleki said in a statement. “While these effects tended to improve over time, they remained significant and abnormally higher in coronavirus patients.”
The more severe the disease, the greater the changes, he added.
The male reproductive system “should be viewed as a vulnerable route of coronavirus contamination and declared a high-risk organ by the World Health Organization,” Maleki said.
A coronavirus unit at Sheba Medical Center
(Photo: AFP)
Experts not involved in the study welcomed the study, but warned that more was needed before firm and quick conclusions could be drawn.
“Men shouldn’t be unnecessarily alarmed,” said Alison Campbell, UK CARE Fertility Group’s director of embryology. “There is currently no definitive evidence of long-term damage caused by coronavirus, to sperm or male reproductive capacity,” she told the London-based Science Media Center.
The results could be biased, she added, by the fact that men recovering from Covid were treated with corticosteroids and antiviral therapies, while the control group was not.
A healthcare professional who performs a serological test for antibodies against the coronavirus
(Photo: Avigayil Uzi)
Allan Pacey, a specialist in male reproductive medicine at the University of Sheffield, put forth a “strong warning” about how the data was being interpreted.
Some of the indicators of decreased sperm quality could 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 was very sick – regardless of the cause – also had to be taken into account, he added.
“We already know that an illness with a fever can affect sperm production, regardless of the cause.”