A new study by Stanford economists shows that giving fathers flexibility to take time off work in the months after their children are born improves the postpartum health and mental well-being of mothers.

In the study, slated for release by the National Bureau of Economic Research on June 3, Petra Persson and Maya Rossin-Slater examined the effects of a reform in Sweden that introduced more flexibility into the parental leave system. The 2012 law removed a prior restriction preventing a child’s mother and father from taking paid leave at the same time. And it allowed fathers to use up to 30 days of paid leave on an intermittent basis within a year of their child’s birth while the mothers were still on leave.

The policy change resulted in some clear benefits toward the mother’s health, including reductions in childbirth-related complications and postpartum anxiety, according to their empirical analysis.

“A lot of the discussion around how to support mothers is about mothers being able to take leave, but we often don’t think about the other part of the equation — fathers,” says Rossin-Slater, an assistant professor of health research and policy.

“Our study underscores that the father’s presence in the household shortly after childbirth can have important consequences for the new mother's physical and mental health,” says Persson, an assistant professor of economics.

Rossin-Slater and Persson are both faculty fellows at the Stanford Institute for Economic Policy Research.

Among their main findings of effects following the reform: Mothers are 14 percent less likely to need a specialist or be admitted to a hospital for childbirth-related complications — such as mastitis or other infections — within the first six months of childbirth. And they are 11 percent less likely to get an antibiotic prescription within that first half-year of their baby’s life.

There is also an overall 26 percent drop in the likelihood of any anti-anxiety prescriptions during that six-month postpartum period — with reductions in prescriptions being most pronounced during the first three months after childbirth.

What’s more, the study found that the average new father used paid leave for only a few days following the reform — far less than the maximum 30 days allowed — indicating how strong of a difference a couple of days of extra support for the mother could make.

“The key here is that families are granted the flexibility to decide, on a day-to-day basis, exactly when to have the dad stay home,” said Persson. “If, for example, the mom gets early symptoms of mastitis while breastfeeding, the dad can take one or two days off from work so that the mom can rest, which may avoid complications from the infection or the need for antibiotics.”

These indirect benefits from giving fathers workplace flexibility are not trivial matters when you consider the health issues mothers often face after childbirth and after they get home from the hospital, says Rossin-Slater, who is also a faculty member of Stanford Health Policy.

Infections and childbirth complications lead to one out of 100 women getting readmitted to the hospital within 30 days in the United States, according to the study.

Meanwhile, postpartum depression occurs for about one out of nine women, and maternal mortality has also been a rising trend over the past 25 years in the U.S.

The study comes as a growing number of lawmakers in the United States vocalize support for paid family leave but have failed to pass federal legislation.

Washington, D.C., and six states have adopted various paid family leave laws, but the U.S. remains the only industrialized nation in the world that does not have a national mandate guaranteeing a certain amount of paid parental leave.

Some federal lawmakers are working on family leave measures and have proposed such legislation over the past few years — including The Family Act, The New Parents Act — but none of them have ever gained enough traction to proceed in Congress.

This new study can help broaden the policy discussions, the researchers say.

The larger context around paid family leave policies is often framed today as a way to help narrow the gender wage gap by giving women more workplace flexibility and fewer career setbacks.

This study, however, shines a light on maternal health costs and how a policy on paid family leave — that includes workplace flexibility for the father — offers more benefits than previously thought, Rossin-Slater says.

“It's important to think not only about giving families access to some leave, but also about letting them have agency over how they use it,” she says.

And when it comes to concerns that fathers might use paid parental leave to goof off instead of spending the time as intended, the researchers say their study should assuage those worries.

“It's not like fathers are going to end up using a whole month to just stay home and watch TV. We don't find any evidence of that,” Rossin-Slater says. “Instead they only use a limited number of days precisely when the timing for that seems most beneficial for the family.”

“For all these reasons,” Persson says, “giving households flexibility in how to use paternity leave makes a lot of sense.”