German scientists have conducted research looking into the quality of sperm in men who contracted coronavirus and results have shown the illness to be conducive to a reduced fertility potential. They compared semen quality between two groups of men: one group that had recovered from the virus and the other that had never contracted it. Researchers at Justus-Liebig University in Giessen, Germany, analysed 84 men with COVID-19 and 105 age-matched control subjects without ever having contracted the disease and took measurements every 10 days for a total of 60 days. Results show overall 'weaker' sperm The sperm that came back from the men who had recovered from the virus was noticeably deformed, less mobile and found in lower concentrations than that of their COVID free counterparts. Though no exact explanation has been given for how coronavirus affects testicles, it is widely known that fever–one of the more common COVID symptoms– has damaging effects on the male reproductive system. Results also showed signs of swelling, sperm cell death and oxidative stress, which is a phenomenon that occurs when volatile chemicals accumulate in living tissues as a result of cells not working at optimal levels. The overall concentration of sperm plummeted by 516% and its mobility went down by 209%. Behzad Hajizadeh Maleki, the lead researcher on the study, said that: 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.More research is needed for conclusive dataSince the effects of COVID-19 have mostly been recorded to affect the respiratory system as well as the heart and blood vessels, there is no clear understanding of how it affects the ability to have children. The sperm collected from the infected progressively improved in quality as more time had elapsed since recovery but, still, the overall effects were worse in men who had a more severe reaction to the virus. And although more research is needed to provide conclusive evidence, experts are advising men who survived COVID-19 to get their reproductive systems checked before trying to conceive.