As a result, the 30-year-old electrician Scott Reed and his wife, Laura, were finding it hard to conceive.
Reed started using his laptop on a table instead and three months later his wife Laura became pregnant with a daughter, the 'Daily Mail' reported.
"I've never heard of this happening before, when the doctors told us it was a real shock," Laura said.
"Scott would use his laptop in the evenings for a couple of hours on and off while we were watching television. He would use it for work and general things like Facebook. We had absolutely no idea the damage it was causing him," she said.
The couple, from Clanfield in Hampshire, visited their doctor after trying for a baby for six months without success.
Initially it was thought Scott's fertility had been affected by mumps, which he had suffered at the age of 21.
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"You don't think it will be that hard to get pregnant. We both went back to have a chat and the doctor put Scott forward for a fertility test," she said.
The couple were then referred to a hospital for tests, which revealed Scott was producing a healthy amount of sperm but they had suffered heat damage.
Under the microscope it was possible to see that the tail of the sperm had coiled around the head, meaning it couldn't swim quickly to the egg.
Biomedical andrologist Sue Kenworthy, from Queen Alexandra Hospital, confirmed the heat of the laptop can have an effect on sperm.
"Scott had been producing a healthy amount of sperm but looking under a microscope I saw that there was heat damage," she said.
"Scott was using his laptop every day and for a few hours. It would get really hot, which would have an effect on his sperm,"
"This showed up under the microscope. The tail of the sperm had coiled around the head.
"This means it can't swim quickly and get to the egg. I would say men should place the laptop on a table, rather than on their lap, as this can make a difference," Kenworthy said.
The problem is common in chefs - who work in hot environments - but can also be caused by laptop computers.
"I never thought using a laptop would affect the quality of my sperm. After asking if I was a chef, the next thing was 'do you use a laptop?" Scott said.
"We carried on trying and we weren't having any luck. We thought it wasn't going to happen so we started planning a trip to travel around Thailand. But then I did a test and found out I was expecting," Laura said.