A University of Michigan study has looked into sleep interruptions among genders, to take care of others.
The study is the first known nationally representative data documenting substantial gender differences in getting up at night, mainly with babies and small children.
And women are not only more likely to get up at night to care for others, their sleep interruptions last longer-an average of 44 minutes for women, compared to about 30 minutes for men.
"Interrupted sleep is a burden borne disproportionately by women. And this burden may not only affect the health and well-being of women, but also contribute to continuing gender inequality in earnings and career advancement," said sociologist Sarah Burgard, a researcher at the U-M Institute for Social Research (ISR).
Burgard analyzed time-diary data from approximately 20,000 working parents from 2003 to 2007, drawn from the U.S. Census Bureau's American Time Use Survey.
The gender gap in sleep interruptions was greatest during the prime childbearing and child-rearing years of the twenties and thirties, she found.
Among dual-career couples with a child under the age of one, 32 percent of women reported sleep interruptions to take care of the baby, compared with just 11 percent of men.
The proportion reporting interrupted sleep declined with the age of the child, with 10 percent of working mothers and 2 percent of working fathers with children ages 1 to 2 reporting sleep interruptions, and just 3 percent of working mothers and 1 percent of working fathers with children ages 3 to 5.
"What is really surprising is that gender differences in night-time caregiving remain even after adjusting for the employment status, income and education levels of each parent. Among parents of infants who are the sole breadwinner in a couple, for example, 28 percent of women who are the sole breadwinner report getting up at night to take care of their children, compared to just 4 percent of men who are the only earner in the couple," Burgard explained.
The findings also have implications for public health interventions to improve sleep.
"Generally, these interventions target individual behaviors, such as the use of alcohol, caffeine or tobacco. Or they focus on nightly routines that help people to relax and fall asleep or stay asleep more successfully. But for parents of young children, the best approach might be discussions and negotiations about whose turn it is to get up with the baby tonight," she concluded.
The study was published in the journal Social Forces.