(Reuters Health)

Physical activity during and after pregnancy improves psychological wellbeing and may protect against postpartum depression, according to a new analysis of existing research.

Even low-intensity exercise, such as walking with a baby stroller, was linked to a lower likelihood of depressive symptoms in new mothers, researchers found.

"The negative consequences of postpartum depression not only affect the mother but also the child, who can suffer poor emotional and cognitive development," said study co-author Celia Alvarez-Bueno of the University of Castilla-La Mancha in Cuenca, Spain.

Postpartum depression, the most common complication of bearing a child, affects 1 in 9 women, according to the U.S. Centers for Disease Control and Prevention. Symptoms can include anxiety attacks, insecurity, irritability, fatigue, guilt, fear of harming the baby and a reluctance to breastfeed.

The symptoms start within four weeks of delivery and are considered severe when they last for more than two weeks, the study team writes in the journal Birth.

"That’s why it’s important to test the most effective strategies to prevent this disorder or mitigate the consequences," Alvarez-Bueno told Reuters Health by e-mail.

The study team analyzed data from 12 controlled trials of exercise interventions during or after pregnancy between 1990 and 2016 that addressed the effects of physical activity on postpartum depression. The studies included a total of 932 women and all examined the severity of postpartum depression, as well as including basic information about the length, frequency, type and intensity of the exercise.

The exercises used in the various studies included stretching and breathing, walking programs, aerobic activity, Pilates and yoga.

Compared to women who didn’t exercise, those who did had lower scores on depression symptom tests during the postpartum period, the researchers found. The apparent benefit of having fewer depression symptoms was seen even among women who did not meet the cutoff for a depression diagnosis.

"We expected that physical activity could reduce postpartum depressive symptoms," Alvarez-Bueno said. "However, we were pleasantly surprised when we found that exercise after pregnancy also reduced depression among the women who didn’t have diagnosable symptoms."

Most intervention programs lasted for three months or longer and recommended three to five exercise sessions per week, but the current study didn’t draw conclusions or provide recommendations about the type or length of exercise that would be most beneficial.

The American College of Obstetrics and Gynecology recommended in 2009 that pregnant and postpartum women engage in 30 minutes of moderate physical activity most days of the week.

"We know that exercise is just as effective as anti-depressants for adults. The trick is to get them to do the physical activity," said Beth Lewis of the University of Minnesota in Minneapolis, who wasn’t involved with the study.

"With postpartum depression, it’s even more complicated due to the increased stress and sleep deprivation after having a baby," she told Reuters Health. "We’re starting to learn more about exercise and how it helps."

Future studies should include more data about the types of physical activity programs that could reduce depression, the study authors write. Health providers should know more about the duration, intensity and frequency of exercise to recommend to new mothers, Alvarez-Bueno noted.

"It remains unanswered how these characteristics improve postpartum depression prevention," she said. "More research addressing this issue is urgently necessary because of the influence on both the mother and child."

Lewis and colleagues are conducting a randomized trial that analyzes home-based exercise and home-based wellness programs among 450 mothers with a history of depression. In another study, they’re analyzing exercise programs among low-income women at risk for postpartum depression.

"Exercise is often the first thing that gets crossed off the list when there’s a new baby," Lewis said. "It’s important to take care of yourself through exercise to keep that wellbeing high."

SOURCE: Birth, online June 7, 2017.