Warning to anyone who suffered a ‘spring cold’ as new study raises fears over male fertility

MEN struck down by a ‘spring cold’ could be at risk of fertility issues, a new study suggests.

Scientists in China found men who caught the Omicron Covid variant – still spreading widely in the UK – had weaker, more damaged sperm than those who didn’t.

The virus is now so common – and symptoms often so mild – that many mistake it for a typical seasonal sniffle.

Recent data from the UK Health Security Agency (UKHSA), as of April 2025, suggests Covid cases are creeping up, with test positivity in hospitals having risen from 4.2 per cent to 4.9 per cent in just two weeks.

And while hospital admissions remain low, this new study suggests the virus could quietly be affecting men’s fertility, up to a month after recovery.

A previous study, published in the Journal Reproduction in 2021, found severe cases of Covid might impact the quality of a man’s sperm.

Experts not involved in the research warned, at the time, that being ill from any virus such as flu can temporarily drop 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 rather than just from being ill,” said Dr Channa Jayasena, from Imperial College London, in an email to CNN.

The latest study, published in Scientific Reports, looked how how badly a mild Omicron Covid infection impacted men’s sperm quality over a month.

To investigate this, experts from China Medical University in Shenyang analysed the sperm of over 600 men – all of whom were seeking fertility treatment at a specialised centre.

This included 140 who gave samples both before and after infection, and 149 healthy men who tested negative throughout.

They also looked at 515 previously infected men in a separate study, comparing them with 89 men who never caught the bug.

One month after testing postive nearly 58 per cent showed reduced sperm count, and around 69 per cent had poorer sperm motility, which is how well sperm move.

The most dramatic fall was seen in the fastest, highest-quality sperm, with 71 per cent showing a drop.

And DNA damage, known to affect pregnancy rates and even increase miscarriage risk, was found in 75 per cent of men post-Covid.

“Further research is needed to observe the long-term effect of Covid on sperm quality or reproductive outcomes,” the scientists wrote in the paper.

“There may be a need to constantly monitor the SARS-CoV-2 infection and integrate screening and diagnosis of the disease in the management of male infertility,” they added.