Men may want to keep their laptops on a desk — just in case they plan on having children. Although there’s debate as to whether keeping your laptop on your lap appreciably impacts sperm health, experts agree that heat is generally bad for testicles, and laptops can get pretty warm. In any case, men who are already struggling with fertility might want to work at their desks.
“The main issue with placing a laptop directly on the lap is the heat transfer from the hot battery on the underside of the laptop to the upper thigh and groin area,” Christopher Sipe, a reproductive endocrinologist with Fertility Centers of Illinois, told Fatherly. Testicles are held in scrotums in the first place to keep them one to two degrees cooler than the rest of the body. “Regular and long-term placement of a laptop on the lap can cause a rise in temperature, which is spermatotoxic and can kill sperm.”
Even men keeping their knees together for prolonged periods can generate enough heat to decrease sperm viability, one study found. This makes an unfortunate scientific case for manspreading, but also suggests that the heat from laptops could pose a problem for fertility. Some research also suggests a link between laptops and scrotal hyperthermia risk, but these findings involved a small sample of men and were conducted in 2005, before technological advances made laptop batteries cooler.
Although heat is a concern (however minor that concern may be), experts generally agree that exposure to electromagnetic frequencies (EMF) from laptops is not. One study that suggested exposure to EMF decreased sperm motility and caused DNA fragmentation had poor methodology; other research claiming that exposure to cell phones caused significant drops in sperm motility failed to look at laptops specifically, and suffered from small sample size. Animal studies are similarly inconclusive.
“There is no science supporting laptop sperm effects,” Richard Honaker, a physician and Chief Medical Officer at Your Doctors Online, told Fatherly. “The heat may reduce counts a tiny bit, but not enough to matter.”