If you've long suspected that mums are more sleep deprived than dads, then you're about to be vindicated.
A new study from the US has discovered that while women become increasingly sleep deprived with every child they have, the sleep habits of dads are relatively unaffected.
Researchers from Georgia Southern University's Jiann-Ping Hsu College of Public Health set out to compare the sleep habits of women with children to their child-free peers.
They conducted a nationwide telephone survey in which they spoke to 5800 men and women about their sleep habits. The researchers asked participants how long they slept each night and how many days they had felt tired in the past month.
Reflecting on the results, assistant professor Kelly Sulivan, the study's lead author, said that 48 per cent of women with children reported only seven hours of sleep or less, compared to 62 per cent of women without children.
In addition, women with young children at home said they were tired 14 days a month, compared to 11 days for those without children in the home.
Among the 3000 women that took part in the study the only factor that corresponded to insufficient sleep was having children.
"Each child in the house increased the odds of insufficient sleep by 50 per cent," Sullivan explained.
"For men, we did basically the same analysis and children had absolutely no impact on men [and their sleep]," she added.
Sullivan said that she couldn't explain why mums and dads had differences in their sleep partners because there wasn't enough data to fully understand what was happening. However she did note that women who are breastfeeding are likely to be sleep deprived because they have to get up for more frequent night time feeds, compared to households where dads can do night feeds too.
There are numerous flaws with the study and experts have warned that it's important not to draw too many conclusions. For example, Jodi Mindell, associate director of the Sleep Centre at Children's Hospital of Philadelphia, told CBS News that men may have been getting more sleep than their partners before they had children.
During her own research, Mindell found that mothers with children from birth to age three typically get less sleep than mothers of children ages three to six.
Mindell suggests parents make a plan as to who is going to take care of household duties, including childcare, so each parent can have a goal of enough sleep.
"It doesn't have to be 50-50, but it's sharing it," she said. If one parent works outside the home during the week and the other doesn't, the stay-at-home parent can cover nighttime child duty while the other parent takes over on weekends, she suggested.
Of course, sleep deprivation isn't a competition, so it's good to find ways for mums and dads to get a little more shut eye. Then again … there is nothing stopping you from using this study to justify a long weekend lie in.