Men who stay up watching late TV have poor sperm counts, an expert claims.
Scientists believe sleep deprivation can cause the immune system to overreact and attack reproductive cells.
Fertility expert Dr Raj Mathu, of Manchester University NHS Foundation Trust, said: “The study suggests men trying for a baby should go to bed early and get a decent amount of sleep.
"They should think about what’s keeping them up and try to change their habits, whether it’s binge-watching Netflix or sending emails.”
The Danish study of 104 couples who had been trying for kids for two years found men in bed by 10.30pm had four times better sperm quality than those staying up after 11.30pm.
The men studied were aged 34 on average.
Prof Christopher Barratt, of Dundee University, said: “If you don’t get enough sleep, that has an impact on the metabolism, which will have a negative effect on sperm quality.”
The findings are presented at the annual meeting of the European Society of Human Reproduction and Embryology (ESHRE).
