It may be tough for working moms to get a good night’s sleep, but working tight hours may affect their children’s sleep, too.

After studying the sleep habits of children from ages 5 to 9, researchers found that when mothers reported less flexibility in their work schedules, their children got less sleep. When they gained flexibility in their work schedules, their children slept more.

However, this link diminished when the researchers accounted for whether the children were given regular bedtime routines, suggesting consistent bedtimes may be the key to offsetting damage done by tight work schedules.

Orfeu Buxton, professor of biobehavioral health at Penn State, said the results give clues into how and why a parent’s work schedule may affect their children’s sleep.

“We’ve seen this link between inflexible work schedules and children's sleep patterns before, but we didn’t know why it was happening,” Buxton said. “Our results suggest that maybe it’s about children not having a regular bedtime routine if their mother is working an inflexible job. We know positive routines especially are very important for positive child growth, so sleep may suffer if it’s not there.”

The researchers said the findings—recently published in the Journal of Child and Family Studies—also suggest that it could be helpful for employers to create policies that give employees more flexibility, both for the health of the employees and their children.

Soomi Lee, now an assistant professor at University of South Florida, who led the paper while a postdoctoral scholar at Penn State, said employers could begin by considering how to change both the structural and cultural practices that may hinder flexibility.

“If workplaces could improve employees’ flexibility and control over when and where they work, that could be helpful,” Lee said. “They could offer diverse flexible work options for employees, especially for working mothers, such as flextime, telecommuting, or job-sharing with another employee.”

Buxton said the study gives parents with inflexible work schedules a way to possibly help their kids get more sleep.

“If parents can be there for their kids on a regular basis, and help them by having a regular bedtime routine, all of that's very beneficial for their long-term growth and development,” Buxton said. “Children can be a delight to watch go to sleep. Perhaps you could start with a bath, then brushing teeth and reading books to create this sort of calm, together time as a family.”

The researchers used data from 1,040 mothers and their children for the study. When the children were 5 and 9 years old, their mothers were asked questions about how flexible they felt their jobs were. For example, if their “work schedule had enough flexibility to handle family needs.”

At each time point, the mothers were also asked if their child had a regular bedtime, if their child had difficulty getting to sleep, and how many hours a night their child usually slept.

Buxton said it was important to measure how flexible the mothers thought their job schedules were, because some employers say their positions are flexible, but only in ways that benefit the employer.

“Many adults, especially low socioeconomic status workers who are single moms, are clock punching,” Buxton said. “In many of these positions, people may be called in at the last minute, or sent home early after planning to be at work for a full day. Or, if they punch in 5 minutes late, they could get written up. These rigid environments are very flexible from the employer’s perspective, but not at all useful to the employee.”

After analyzing the data, the researchers found that overall, less workplace flexibility was associated with shorter child sleep time. An increase in workplace flexibility from when a mother's child was 5 to when he or she was 9 was associated with children sticking to their bedtimes better and a 44% lower chance of the child having trouble getting to sleep.

Lee said that in addition to having implications for workplace practices, the findings also suggest ways health-care workers can help families.

“Previous research has shown that early bedtime practices can have long-term influences on individual sleep,” Lee said. “Clinicians and practitioners could consider speaking with working mothers about how to improve their children’s bedtime routines. Future research could also continue to identify other modifiable factors linking parents’ work and child sleep, so we can intervene to promote sleep health from childhood and to reduce future sleep health disparities.”

Buxton and colleagues are continuing this research to the next study, in the transition to young adulthood, how sleep health trajectories may contribute to the emergence and persistence of modifiable disparities in sleep and well-being.