Scientists in China have raised concerns the new coronavirus, named COVID-19, may affect male fertility. However, experts in the field has stressed to Newsweek that men should not be worried.
Chinese researchers were looking at existing data on a receptor that COVID-19 is thought to use to infect human cells. They found it is highly expressed in the cells of the testes and kidneys.
It is not clear if the data included any COVID-19 patients, and does not feature data on the fertility of those who have caught the infection.
This prompted concerns COVID-19 could damage the testes and kidneys. The team advised healthcare workers to keep an eye on their patient's kidneys, as well as fertility in men. The article was published on medRxiv, a website where researchers publish work that has not been peer-reviewed in order to spark discussions with other experts.
"Clinicians should pay attention to the risk of testicular lesions in patients during hospitalization and later clinical follow-up, especially the assessment and appropriate intervention in young patients' fertility," they wrote.
The scientists said they were interested in exploring whether COVID-19 has the potential to harm the urinary and male reproductive systems after some patients were found to have abnormal kidney function and damage, in addition to the expected problems with the respiratory system.
However, Professor Allan Pacey, a leading expert in male fertility at the University of Sheffield in the U.K., emphasized the article is a "short discussion" paper which has not been peer-reviewed and is "highly theoretical." It is intended to alert the medical and scientific community to the possible impact COVID-19 may have on the male reproductive system, he said.
"At present it is somewhat premature to conclude from this study [that] COVID-19 will definitely affect male fertility, but it is useful that the authors have raised this concern so that researchers can in due course take a look at the fertility of those who were infected by COVID-19," he said.
Professor Richard Sharpe, a world-renowned expert in fertility at the MRC Centre for Reproductive Health at the University of Edinburgh, U.K, told Newsweek the study presented a "reasonable speculation without any direct supporting evidence."
The new member of the coronavirus family has killed over 2,000 people in more than 75,000 cases since late last year. People have predominantly fallen ill in the central Chinese province of Hubei, where the virus is thought to have spread from workers at a wholesale seafood market in the city of Wuhan. Just over 1,000 COVID-19 cases have been confirmed outside of mainland China, in countries and territories including the U.S. and Hong Kong, as shown in the infographic below by Statista.
"Given the scale of the COVID-19 infection and its localisation at the moment largely to Wuhan, I think it would be very useful for those involved in the care of those men infected by COVID-19 to consider doing some long term follow-up of their reproductive function," Pacey said, adding: "That would quickly establish whether or not there is a potential problem here."
Pacey said those who are concerned about their fertility after falling ill with COVID-19 should discuss this with their family doctor. Men can have a "relatively simple" semen analysis to determine whether their fertility has been affected, he said.
"However, since it takes about three months to produce sperm, any test performed shouldn't be done too soon. Men should wait at least three months before being tested," Pacey said.
He suggested the tests my be more valuable for experts looking at the potential link between COVID-19 and male fertility on a population-wide scale rather for individuals.
"The problem in interpreting the results from semen analysis is that for most men who are infected with COVID-19, they wouldn't have had their fertility tested beforehand, so it is going to be very difficult with an individual man to know if any abnormal test result was due to the virus or not," he said.
"However, across a large population of men (several hundred) it should be possible to see if rates of poor sperm quality are higher than what might be predicted."
Those worried about COVID-19 and fertility to focus on their general and respiratory health and controlling any fever, Sharpe advised, adding: "There's not much else you can do."
Commenting on male fertility more generally, Sharpe explained the spike in body temperature caused by viruses is "bad news for sperm production" as the cells need to be at 3 to 4 degrees Celsius lower than the core body temperature.
"Anything that elevates core/testicular temperature is potentially damaging to sperm production," he said.
This article has been updated with comment from Professor Richard Sharpe.