Moving more for a healthy pregnancy

When Noelia M. Zork, M.D., was pregnant, she wanted to do everything she could to avoid having gestational diabetes — high blood sugar that typically develops between the second and third trimester. Diabetes runs in her family, and because her blood sugar levels were borderline high during her pregnancy, Zork, a maternal-fetal medicine specialist and researcher at Columbia University Irving Medical Center, followed the advice she gives patients: Find ways to stay active and follow a heart-healthy diet. 

“If you can do small things, they add up,” she explained. This worked to offset her risks. In addition to eating well, she focused on simple activities she could do at home, like a pregnancy-focused yoga video a few times a week. After having her second child, she walked to the park with her family and they danced to free children’s Zumba videos. “It’s about batching in activity while you’re entertaining the child,” she said. “Anything that gets the heart rate going counts.”

Studies confirm it. For years regular physical activity has been linked to healthier pregnancies and better outcomes for new moms and babies. Several studies, including those from the NIH-supported nuMoM2b and nuMoM2b Heart Health Study network, have found that people who can stay physically active throughout pregnancy not only have a reduced likelihood for developing gestational diabetes, but are more likely to have lower blood pressure during and after pregnancy. Other studies have found that regular physical activity supports a healthy body weight during and after pregnancy, while reducing symptoms of postpartum depression. 

It’s why researchers continue to study the positive effects of physical activity and how to help people move more throughout their lives, including during pregnancy.  

All the powerful perks

“Exercise helps you sleep better at night, lowers anxiety, and reduces blood pressure for up to 24 hours,” said Bethany Barone Gibbs, Ph.D., a nuMoM2b network researcher and principal investigator of the Gibbs Physical Activity and Sedentary Behavior Research Lab at West Virginia University. “This happens every time you exercise.”

The long-term benefits are just as important. Regular physical activity supports bone health, the brain, a normal body weight, metabolic and physical functions, and offsets risks that can lead to a heart attack, stroke, diabetes, certain forms of cancer, and dementia. 

This is why the Department of Health and Human Services recommends that adults without underlying health complications get at least 150 minutes each week of moderate-intense physical activity, like brisk walking or easy cycling. The recommendations can also be met with 75 minutes of weekly vigorous exercise, like taking a fast-paced aerobics class. Adults should also incorporate at least two weekly strength-based sessions, which can include body-weight exercises, into their routine. 

The guidelines for physical activity during pregnancy are the same but encourage women who haven’t participated in vigorous activities to focus on moderate-intense activity. People who are pregnant should avoid exercising in extreme heat, contact sports that increase risks for falling, and doing exercises while lying on their spine after the first trimester. 

“Even committing to 10 minutes at a time, three days a week, is going to make a huge difference,” said Zork. For people new to exercise, she and others recommend a gradual increase in physical activity. Think of working up to 10 minutes of marching in place a few times each day. 

According to research from the nuMoM2b study, first-time moms who increased their physical activity throughout the first half of pregnancy were less likely to develop gestational diabetes compared to those who were the least active. Among the more than 10,000 study participants, 5.7% of those who did not participate in physical activity developed gestational diabetes. This dropped to 3.8% for those who gradually increased their activity levels and to 3.1% for the most active participants. 

“Taking steps to support heart-healthy living, such as by moving more and knowing numbers for a healthy heart, supports individual health and well-being and helps create a healthy environment for the baby to grow and develop,” said Jasmina Varagic, M.D., Ph.D., program director of the Vascular Biology and Hypertension Branch in the Division of Cardiovascular Sciences at NHLBI. These outcomes — positive pregnancy experiences and optimal indicators of heart health — have also been linked to better health outcomes years later. 

A new research frontier

As investigators study the many benefits of physical activity, they are also conducting research to specify how to “sit less and move more” each day. 

Gibbs is studying these effects during and after pregnancy. Her research in this area started with a pilot study with 120 women during their pregnancy. She and researchers measured how many times participants stood, sat, and stepped each day. They also tracked moderate-intense activities and sedentary behavior, or time spent sitting, reclining, or lying down. At the end the study, 19 participants experienced at least one adverse pregnancy outcome, such as gestational diabetes, complications related to high blood pressure, or a preterm birth.

Among those who experienced complications, 16 fell into a “high-sitting” category, a pattern that included sitting or reclining for about 11 hours a day and getting around 5,000 daily steps. Those who sat for less than 9 hours a day logged about 7,000 steps and were largely protected from the same risks. The associations between pregnancy complications and “high-sitting/low steps” were also independent from moderate-intense activities. 

Gibbs and her colleague Kara M. Whitaker, Ph.D., M.P.H., at the University of Iowa are now studying these patterns among 500 women through an NHLBI-supported study called Pregnancy 24/7. “Even if you are getting 30 minutes a day of physical activity — that’s only 3% of the time you are awake,” she said. “We want to understand what’s happening the rest of that time and how it relates to a healthy pregnancy.”

To study these patterns after pregnancy, Gibbs and other researchers are partnering with women in the nuMoM2b Heart Health Study to assess how daily movement overlaps with cardiovascular health. In the meantime, Gibbs encourages people, especially busy moms, to try to work physical activity into their day, however and whenever they can. 

“Women do a lot,” said Gibbs. “It doesn’t have to take a lot of time, but caring for yourself with physical activity is really important and can have so many benefits.”