Women who engage in light physical activity and reduce sedentary time may significantly lower the risk of key health problems during pregnancy, according to a University of Iowa-led study released on June 10.
The research involved 470 pregnant women across all stages of pregnancy. Each participant wore monitors that measured their physical activity in 24-hour cycles and recorded sleep duration. Based on the observational data, researchers proposed a "Goldilocks Day"-like guide for pregnant women, which could reduce by nearly 30% the risk of developing hypertensive disorders of pregnancy (HDP), including chronic hypertension, gestational hypertension, and preeclampsia.
The recommendations from the study include reducing sedentary time to fewer than eight hours each day, engaging in at least seven hours of light physical activity daily, participating in about 22 minutes of moderate to vigorous physical activity such as brisk walking each day, and getting nearly nine hours of sleep per night. Sedentary behavior is defined as being mostly inactive—such as sitting or lying down—while light physical activity can include casual walking or simply standing.
Kara Whitaker, associate professor in the Department of Health, Sport, and Human Physiology at Iowa and corresponding author for the study, said: "We are identifying the optimal composition of movement behaviors across the day associated with the lowest risk of developing HDP and the most improved health outcomes. This blueprint holds for each and every trimester of pregnancy." Whitaker also said, "Just moving around more seems to have significant health benefits," adding that this may be a more feasible target for pregnant women who do not exercise regularly.
Data from participants showed a steep increase in HDP risk when sedentary time exceeded ten hours per day. Women who increased their light physical activity to at least four hours daily reduced their HDP risk from 30% to 15%. The researchers noted no appreciable benefit from longer durations of moderate to vigorous activity or excessive sleep beyond recommended amounts. "Through this study, we are providing evidence that reducing sedentary behavior and engaging in light physical activity are important, and maybe more important, when it comes to pregnancy and health," Whitaker said.
Whitaker emphasized that knowing which mix of behaviors has the greatest impact during pregnancy is crucial because clinical research has shown that women who develop HDP are more than twice as likely to develop heart disease later in life. She said, "We know that cardiovascular disease is the number one killer of women, and if we can intervene in pregnancy and prevent women from developing a hypertensive disorder...we are putting them on a better trajectory...toward more optimal cardiovascular health."
