WVU study shows pregnant women who sit less and move more have fewer adverse outcomes

A study by researchers at West Virginia University and two other university-affiliated medical centers found a greater-than-expected significance in the risk of adverse pregnancy outcomes, including gestational diabetes and preeclampsia, for women who spend more time sitting compared to those who include even light activity in their daily routines.

“The big finding was that women who were sitting for over 10 hours a day were developing twice as many adverse pregnancy outcomes as women who were sitting for shorter amounts of time,” said Bethany Barone Gibbs, professor and chair of the WVU School of Public Health Department of Epidemiology and Biostatistics and co-investigator of the study.

“We were expecting to find that more sitting may be less healthy in pregnancy, but the magnitude of extra risk was bigger than we thought it would be. Our study supports the idea that a daily activity pattern with lots of prolonged sitting should be discouraged during pregnancy.”

The study, published in the Journal of the American Medical Association, shows that two in five women who sat for 10 or more hours a day had an adverse pregnancy outcome, while only one in five women who sat approximately seven hours a day experienced an adverse pregnancy outcome.

Adverse pregnancy outcomes measured in the study included gestational hypertension, preeclampsia, gestational diabetes, preterm birth and small for gestational age. These pregnancy complications can be harmful to the mother and baby during pregnancy and also may have long-term health consequences.

For example, preeclampsia is a serious and potentially life-threatening blood pressure disorder that occurs during pregnancy and postpartum. It is characterized by a rapid rise in blood pressure that can lead to seizure, stroke, multiple organ failure and even death of the mother and/or baby. Women who had preeclampsia have a much greater risk of developing cardiovascular disease later in life.

Gestational diabetes develops during pregnancy in women who were not previously diagnosed with the disease. Although it normally goes away after the baby is born, it increases the mother’s likelihood of developing Type 2 diabetes later in life. 

“These adverse pregnancy outcomes, especially preeclampsia and gestational hypertension, have become much more common in the last two decades,” Barone Gibbs said. “From a public health perspective, it’s very concerning. We are looking for solutions to decrease these outcomes because currently there are very few options.”

While moderate- to vigorous-intensity exercise is one of the few things that can lower the risks for adverse pregnancy outcomes, Barone Gibbs said that level of activity might not be an option for some pregnant women. She and her colleagues reasoned that not all pregnant women have the resources or accessibility to the kinds of supervised exercise plans available in gyms and workout studios. They also considered that pregnant women might not feel like they have the physical energy to put into an exercise regimen.

“It’s one thing to say, ‘everyone should exercise,’ but we know there are a lot of barriers to that, especially for pregnant women because they’re fatigued, they have nausea, their bodies are changing and they have musculoskeletal pain,” Barone Gibbs said. “We wanted to think about some alternatives for pregnant women to be active but not at the level of a supervised exercise plan.” 

Instead, the study aimed to determine whether sitting less and moving more at light intensity would be related to lowering the risks. The idea that too much sitting could worsen pregnancy outcomes builds upon research from as recently as a few decades ago when providers recommended bed rest or activity restriction for women who developed certain pregnancy complications. But despite the common practice, research following these women found that changing to a very low level of activity was not helpful and, in some cases, actually led to worse outcomes like more preterm births and preeclampsia.

“Since our modern lifestyle has engineered most required physical activity out of our days, many pregnant women inadvertently have activity patterns that actually look a lot like activity restriction even if was not prescribed,” Barone Gibbs said.

For the multi-site study, the team recruited 500 women in their first trimester of pregnancy from West Virginia, Pennsylvania and Iowa. The women were equipped with activity monitors attached to their legs to measure how much they were sitting and whether they sat for longer sessions.

In addition to WVU, monitoring was conducted at the University of Iowa, led by Kara Whitaker who served as the study’s principal investigator, and the University of Pittsburgh.

The WVU research team included postdoctoral fellow Katrina Wilhite, doctoral students Elly Marshall and Brianne Nichols, and Sarah Modlin, a research associate in the WVU School of Public Health Department of Epidemiology and Biostatistics, and Alexis Thrower, a doctoral student in WVU School of Medicine Department of Exercise Physiology. Dr. Iqra Sheikh, assistant professor in the WVU School of Medicine Department of Obstetrics and Gynecology and a physician at WVU Medicine, served as a study collaborator.

Funding for the study was provided by the National Heart, Lung, and Blood Institute, a part of the National Institutes of Health.

Researchers recorded the women’s activity patterns at every trimester throughout their entire pregnancy until the babies’ births to determine how activity patterns correlated to adverse pregnancy outcomes.

Barone Gibbs explained that, while the data suggests that pregnant women should be sitting less and moving more, a larger clinical trial would further validate the findings.

“Our findings suggest it doesn’t necessarily have to be exercise, just getting up and moving around more may help you avoid these pregnancy complications,” she said.

Barone Gibbs said she hopes the study encourages pregnant women to monitor the amount of time they’re sitting and the amount of activity they incorporate into their days. She suggests wearable devices that can provide prompts and monitor steps.

“Most of these will give you a reminder if you’re sitting for an hour that it’s time to get up and start moving around a bit, take a little walk or just do something,” she said.

“If they don’t have access to a wearable, set a reminder on your phone or computer that it’s time to get up and do something to get your blood flowing. Another thing we tell pregnant women in interventions is, ‘listen to your body.’ If they’ve been sitting for a long time and their back hurts or they have discomfort, it’s time to get up and move around.”