Smartphone use at night ‘reduces male fertility’

Exposure to light-emitting devices before sleep is linked to decline in men’s sperm quality, study finds

MEN who reach for their smartphone at night are damaging their fertility, a study has shown for the first time.

Greater exposure to the screens of light-emitting devices before bedtime is associated with a decline in sperm quality, according to scientists.

The researchers obtained semen samples from 116 men aged between 21 and 59 who were undergoing fertility evaluation.

Men who reported using their phone more in the evenings had a reduced concentration of sperm, and their sperm had less “motility” – the ability to swim correctly.

Radiofrequency electromagnetic radiation emitted from mobile phones was one factor associated with these changes, the scientists said, as it raised the temperature of the sperm, interfering in its production.

Testicles should be kept cooler than the rest of the body in order to produce the best quality sperm, according to the NHS website. It notes that wearing tight underwear can increase their temperature by up to 1C.

Dr Amit Green, who led the study at the Sleep and Fatigue Institute in Tel Aviv, Israel, said: “Smartphone and tablet use in the evening and after bedtime was correlated with decline in sperm quality. Furthermore, smartphone use in the evening, tablet use at bedtime, and television use in the evening were all correlated with the decline of sperm concentration.

“To the best of our knowledge, this is the first study to report these types of correlations between sperm quality and exposure time to short-wavelength light emitted from digital media, especially smartphones and tablets, in the evening and after bedtime.”

The study, published in the journal Sleep, said the past few decades have been “characterised by the widespread usage of digital devices [and] reports of male fertility decline”.

It also found that men who slept for longer had a higher sperm count and sperm with better motility.

Previous studies have explored potential links between the use of mobile phones and sperm quality.

Researchers from the Carmel Medical Centre, in Israel, reported that men who spoke on their phone for more than an hour every day were more likely to have an abnormal concentration of sperm.

A study by the Cleveland Clinic Foundation, in Ohio, concluded that keeping phones in front pockets for more than four hours every day was associated with poorer sperm quality.

“Evidence does suggest sperm quality has dropped over the past few decades,” according to the NHS.

“The now ubiquitous use of smartphones in developed countries, and the corresponding exposure to radiofrequency electromagnetic radiation, could be one factor.”