Covid 19 coronavirus: Covid may damage male fertility, study finds

A firefighter receives his second dose of the Covid-19 vaccine in Los Angeles on January 27. Photo / AP

Covid-19 could damage male fertility, an experimental study has suggested for the first time.

Scientists in Germany found significant deterioration in semen quality in men up to 60 days after the illness. They also noted higher markers of inflammation, oxidative stress and sperm cell death, all indicators affecting a man's chance of fathering a child.

The researchers recommended that men who have suffered badly from Covid-19 should have their reproductive health evaluated before trying for a baby. However, they caution that the results of their laboratory study may not necessarily translate to poorer reproductive ability.

Other experts have pointed out that longer studies are needed to establish the extent to which semen quality improves over time.

The team at Justus-Liebig University analysed 84 men with confirmed Covid-19 and 105 age-matched control subjects, who had not contracted the virus. They took measurements every 10 days over a 60-day period.

In the men with Covid, markers of inflammation and oxidative stress in sperm cells were more than double that of the healthy cohort. Sperm concentration was reduced by 516 per cent, mobility by 209 per cent and sperm cell shape was altered by 400 per cent.

The researchers said this represents oligoasthenoteratozoospermia, which is one of the most common causes of subfertility in men.

There has been concern since the Covid virus emerged about its effect on male reproduction because the same receptors the virus uses to gain access to the tissues of the lungs are also found in the testicles.

Behzad Hajizadeh Maleki, a PhD student who led the research, said: "These effects on sperm cells are associated with lower sperm quality and reduced fertility potential. Although these effects tended to improve over time, they remained significantly and abnormally higher in the Covid-19 patients, and the magnitude of these changes were also related to disease severity."

He added: "The results from this study also suggest that the male reproductive system should be considered a vulnerable route of Covid-19 infection and should be declared a high-risk organ by the World Health Organisation."

Professor Allan Pacey, an expert in andrology at the University of Sheffield, urged caution in interpreting the results.

"That the study was able to repeat these measurements every 10 days over a 60-day period is no mean feat and this is a nice part of the study," he said.

"However, since sperm production takes just under three months, roughly, to be completed from start to finish, in my opinion they ended the study 30 days too soon."

Dr Channa Jayasena, reader in reproductive endocrinology and andrology, Imperial College London, said: "Being ill from any virus such as flu can temporarily drop your sperm count (sometimes to zero) for a few weeks or months.

"This makes it difficult to work out how much of the reductions observed in this study were specific to Covid-19 rather than just from being ill.

"This study suggests there may be an inflammatory response in the testes following Covid-19, which makes it more plausible that Covid-19 influences male fertility. This makes it important to study the long-term effects of Covid-19 on male fertility."