Coronavirus can affect sperm quality and reduce fertility in men, according to a new study based on experimental evidence.
The viral disease – which has swept the globe, killing nearly 2.2 million lives – could increase sperm death, inflammation and so-called oxidative stress, researchers reported in the journal Reproduction on Friday.
A medical worker in Jerusalem is performing tests for coronavirus
(Photo: AFP)
These findings provide the first direct experimental evidence that the male reproductive system could be targeted and damaged by coronavirus, the authors concluded.
Experts who commented on the research, however, said the virus’s ability to compromise male fertility remains unproven. Coronavirus causes respiratory diseases, especially in the elderly and those with basic medical problems.
The world has seen more than 100 million confirmed cases since the disease appeared in central China in late 2019.
Transmitted by respiratory drops, the disease attacks the lungs, kidneys, intestines and heart.
Previous studies have also shown that it can infect male reproductive organs, affecting the development of sperm cells and disrupting reproductive hormones. The same receptors used by the virus to access lung tissue are found in the testicles.
A coronavirus department at Ziv Medical Center in Safed
(Photo: Aviho Shapira)
But the effects of the virus on men’s ability to reproduce remained unclear.
Behzad Hajizadeh Maleki and Bakhtyar Tartibian from Justus-Liebig University in Germany looked for biological markers that could indicate a negative impact on fertility.
The 10-day analysis for 60 days in 84 men with coronavirus was compared with data for 105 healthy men.
In patients with COVID-19, sperm showed a significant increase in markers of inflammation and oxidative stress, a chemical imbalance that can damage DNA and proteins in the body.
“Strong note of caution”
“These effects on sperm cells are associated with lower sperm quality and reduced fertility potential,” Maleki said in a statement. Although these effects tended to improve over time, they remained significantly and abnormally high in coronavirus patients.
The more severe the disease, the greater the changes, he added.
The male reproductive system “should be considered a vulnerable pathway for coronavirus infection and declared a high-risk organ by the World Health Organization,” Maleki said.
A coronavirus ward at Sheba Medical Center
(Photo: AFP)
Experts who were not involved in the study welcomed the research, but warned that more was needed before drawing hard and quick conclusions.
“Men should not be unjustifiably alarmed,” said Alison Campbell, director of embryology at CARE Fertility Group in the UK. “There is currently no definitive evidence of long-term damage from coronavirus, sperm or male reproductive potential,” she told the Science Media Center in London.
The results could have been distorted, she added, by the fact that men recovering from Covid were treated with corticosteroids and antiviral therapies, while the control group was not.
A medical worker performing a serological test to detect coronavirus antibodies
(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 several men in the coronavirus group were overweight.
The mere fact that only one group was very ill – for whatever reason – had to be taken into account, he added.
“We already know that a febrile illness can have an impact on sperm production, no matter what caused it.”