(Independent) Getting an early night could help men conceive, according to a new study which found those who hit the hay before 10.30pm were up to four times more likely to have good quality sperm.
Men who got around eight hours a night were also more likely to have healthy sperm than those who got less than seven, the researchers from Aarhus University, Denmark.
Fertility experts said the findings suggest couples looking to conceive should consider limiting distractions that might keep them up at night, such as checking emails or sitting in front of a Netflix box set.
The latest findings study looked at sleep patterns of around 100 male volunteers who were attending fertility clinics in Denmark, 48 of whom had healthy sperm and 56 with low-quality sperm.
Men who went to bed before 10.30pm were four times more likely to have healthy sperm than night owls who stayed up past 11.30pm.
They were 2.75 times more likely to have healthy sperm than men who went to bed at a “normal time” between half past 10 and half past 11.
Not getting enough sleep could be even more harmful, as the research suggests men who got less than seven hours sleep a night were as much as six times more likely to have poor sperm.
Sleep plays a key role in moderating hormones and stress levels that can affect fertility, and sleep deprivation stress can cause the immune system to overreact and attack sperm.
“These were men who had been trying to have a baby for about two years and an early bedtime was likely to be important because it allowed them to get more sleep,” said Professor Hans Jakob Ingerslev, co-author of the study from Aarhus University.
“The reasons could be psychological as sleep-deprived men suffer mores stress and that can have an impact on fertility.”
Professor Ingerslev and his colleagues also looked at overall sleep quality, but did not find a link between disrupted sleep – from getting up in the night to use the toilet, for example – and sperm quality.
The findings were presented as a poster at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE) in Vienna and have not yet been published in a peer-reviewed journal.
However independent experts said they offered sound advice for men struggling to conceive.
“They should think about what is keeping them up and try to change their habits, whether it’s binge-watching Netflix or sending emails,” said Dr Raj Mathur, a consultant gynaecologist at Manchester University NHS Foundation Trust.
“Going to bed earlier with their partner may also increase their opportunity for sex, improving their chances of success further.”