Men who recover from moderate or severe COVID-19 symptoms may have reduced fertility, a new study has claimed.
The unpublished research, conducted by Professor Dan Aderka of the Sheba Medical Centre in Tel Aviv, Israel, reported that the virus was present in 13 percent of sperm samples taken from screened COVID-19 patients. He also found a 50 percent reduction in sperm volume, concentration, and motility in patients with moderate symptoms 30 days post diagnosis.
'As normal sperm maturation takes 70 to 75 days, it is possible that if we are doing a sperm examination two and a half months after recovery, we may see even more reduced fertility,' said Professor Aderka speaking to the Jerusalem Post.
The study also reported changes in two types of cells in the testes of post-mortem tissue from 12 patients. The cells, called Sertoli and Leydig cells, are required for sperm maturation and testosterone production (the hormone that induces sperm division and multiplication), respectively. Professor Aderka believes this is due to the virus binding to ACE2 receptors found on both cell types, after which the cells die. This, he suggests, leads to infertility.
Professor Aderka is unsure whether these effects are reversible or persist long term. He also suggested that doctors will need to examine the same patients in six months and a year to determine whether the damage 'stands the test of time'. This is something his team is planning to do.
Given the results of his study, Professor Aderka also plans on investigating an enzyme called TMPRSS2. 'TMPRSS2 assists the virus in binding to the ACE receptor, facilitating its internalisation into the cells. This phenomenon may explain the higher COVID-19 morbidity and mortality of men compared to women,' he told the Post.
However, the research is unpublished and has not been peer-reviewed. Professor Allan Pacey, a leading expert in male fertility at the University of Sheffield, speaking to MailOnline, said he wouldn't be surprised if coronavirus caused a transient reduction in sperm production.
'People who get coronavirus are probably quite unwell, even influenza will cause a decline in sperm count temporarily,' he said. 'The question is whether it is permanent and whether it is recoverable.'
Professor Pacey also pointed out deceased patients would have been much sicker than the average infected man, and are likely to have been older, which would also explain reduced sperm count. 'There's a bit of caution there because if you're in ICU and you die you're very sick, so we shouldn't be surprised if there are changes in the testicles,' he said.
Referring to the reported 13 percent of sperm samples containing the virus, he added 'we've done work on other viruses, for example chlamydia, a bacterium that behaves like a virus, and it's really difficult to prove if the virus is inside the sperm.'