“This report provides the first direct evidence to date that COVID-19 infection impairs sperm quality and male reproductive potential,” the study said.
However, experts not involved in the study were immediately skeptical of the report’s conclusion and urged caution in overgeneralizing the study results.
“I must take great care in their interpretation of these data. For example, the authors state that their data shows that ‘COVID-19 infection causes significant impairment of male reproductive function,’ but it really only shows an association,” said Allan Pacey. , a professor of andrology at the University of Sheffield in South Yorkshire, UK, via email.
“Being sick with a virus like the flu can temporarily lower your sperm count (sometimes to zero) for a few weeks or months. This makes it difficult to figure out how many of the reductions seen in this study were specific to COVID-19 than just being sick, ”said Dr. Channa Jayasena, a consultant in reproductive endocrinology and andrology at Imperial College London, in an email.
In addition, “it is important to note that there is no evidence of the Covid-19 virus in semen and there is no evidence that the virus can be transmitted through semen,” said Alison Murdoch, head of the Newcastle Fertility Center at the International Center. in front of Life, Newcastle University in the UK, via email.
Small study of 84 men
In the study, 105 fertile men without Covid-19 matched 84 fertile men diagnosed with coronavirus and analyzed their semen at 10-day intervals for 60 days.
Compared to healthy men without Covid-19, the study found a significant increase in inflammation and oxidative stress in sperm from men with Covid-19. Their sperm concentration, mobility and shape were also negatively affected by the virus.
The differences widened with the severity of the disease, the study found.
“These effects on sperm are associated with lower sperm quality and reduced fertility potential. While these effects improved over time, they remained significantly and abnormally higher in the COVID-19 patients, and the magnitude of these changes was also related to the disease severity, ”lead researcher Behzad Hajizadeh Maleki, a doctoral student at Justus Liebig University Giessen, in Hesse, Germany, said in a statement.
There were also much higher levels of ACE2 enzymatic activity in men with Covid, the study found. ACE2, or angiotensin-converting enzyme 2, is the protein that provides the entry point for the novel coronavirus to attach and infect a wide variety of human cells
However, it is not surprising that Covid-19 can affect the male reproductive system because ACE2 receptors, or the same receptors that the virus uses to access the tissues of the lung, are also found in the testicles, ” said Pacey. he is also editor-in-chief of the magazine Human Fertility.
A constant concern
“Since the beginning of the Covid-19 pandemic, there has been an understandable (but theoretical) concern about whether this coronavirus could adversely affect the fertility of men who become infected,” said Pacey.
After reviewing about 14 studies published on the topic, Pacey said he concluded that “any measurable effect of coronavirus on male fertility was likely only minor and transient.”
The findings of this study, he added, could be due to other factors, such as the use of medications to treat the virus, which the authors also acknowledged in the study.
“Therefore, in this dataset I only see possible differences in the sperm quality between men who are ill with a fever (fever). and those who were healthy. We already know that an illness with a fever can affect sperm production, regardless of the cause, ”said Pacey.
Sheena Lewis, professor emeritus at Queen’s University Belfast in Ireland, shared similar thoughts via email: “I am concerned that the men with COVID were significantly higher in body weight and were undergoing some therapeutic treatments.
“We know that obesity only decreases sperm quality. The COVID treatments may also have affected the sperm quality of these men, rather than COVID itself,” Lewis said.
“Longer term studies are therefore needed before the testes are considered a high-risk organ specific to Covid-19,” said Murdoch of Newcastle.