Less Sedentary Time & More Light Activity May Lower Pregnancy Hypertension Risk

Increasing everyday movement, even light activity and reducing prolonged periods of sitting may significantly lower the risk of developing hypertensive disorders of pregnancy, according to research presented at the American Heart Association’s EPI | Lifestyle Scientific Sessions in March 2026. The findings underscore the importance of counseling pregnant individuals not just about dedicated exercise, but also about overall movement patterns throughout the day.

Beyond Exercise: The Role of Daily Movement

The study, led by Kara M. Whitaker, PhD, MPH, FAHA, of the University of Iowa, examined the relationship between 24-hour movement behaviors – including light-intensity physical activity, moderate to vigorous physical activity, sedentary time, and sleep – and the risk of gestational hypertension or preeclampsia. Researchers tracked the activity of 470 pregnant women (aged 18-45, with 83% identifying as non-Hispanic white) using wearable devices over multiple trimesters, following them until six weeks postpartum. The data revealed that sedentary behavior and light physical activity were the most influential modifiable factors linked to hypertensive disorders of pregnancy.

“We began this research because there is a major gap in knowledge about how sedentary behavior and light-intensity physical activity relate to pregnancy complications, particularly hypertensive disorders of pregnancy,” Dr. Whitaker told Healio. “Remarkably, little is known about these behaviors and how it relates to pregnancy health. We wanted to understand how all 24-hour movement behaviors across pregnancy, not simply exercise, might influence the risk of developing a hypertensive disorder of pregnancy.”

Hypertensive disorders of pregnancy, encompassing gestational hypertension and preeclampsia, are serious conditions characterized by high blood pressure that develops during pregnancy. Preeclampsia, in particular, can lead to severe complications for both mother and baby, including preterm birth, organ damage, and even death. Understanding modifiable risk factors is crucial for improving maternal and fetal health outcomes.

Defining Optimal Activity Patterns

The research identified an “optimal” daily activity pattern associated with a substantial reduction in risk. This pattern involved approximately 6 hours of sedentary behavior, 8 hours of light physical activity, 4 minutes of moderate to vigorous physical activity, and 10 hours of sleep. Women adhering to this pattern demonstrated a 54% lower risk of developing a hypertensive disorder compared to those with a typical daily activity pattern. Even more strikingly, this optimal pattern was linked to a 78% risk reduction when compared to those with the least healthy activity levels.

The study highlighted that exceeding 10 hours of daily sedentary time or engaging in less than 5 hours of light physical activity significantly increased the risk. This suggests that even small changes in daily routines – such as taking frequent breaks to stand and walk around, or incorporating light chores into the day – could have a meaningful impact.

What Does This Mean for Pregnant Individuals?

These findings reinforce the growing body of evidence emphasizing the benefits of reducing sedentary behavior and increasing physical activity for overall health. However, this study specifically points to the importance of these behaviors during pregnancy, a period when women are particularly vulnerable to developing hypertensive disorders. It’s important to note that the study did not prescribe specific exercise regimens; rather, it focused on the impact of everyday movement patterns.

“While moderate to vigorous physical activity (exercise) has many important benefits, our data suggest that addressing lower-intensity behaviors may be especially critical for reducing risk of developing a hypertensive disorder of pregnancy,” Dr. Whitaker explained. “This aligns with current guidelines encouraging patients to ‘sit less and move more.’”

Study Details and Limitations

The Pregnancy 24/7 cohort study utilized activPAL3 micro and Actiwatch Spectrum Plus wearable devices to objectively measure movement behaviors. Participants were enrolled before 13 weeks’ gestation between 2021 and 2024 at sites in Iowa, Pennsylvania, and West Virginia. While the study provides valuable insights, it’s important to acknowledge its limitations. The sample population was predominantly non-Hispanic white, which may limit the generalizability of the findings to more diverse populations. Further research is needed to confirm these results in a broader range of ethnicities and socioeconomic backgrounds.

the study established associations between movement behaviors and hypertensive disorders, but it cannot prove causation. Other factors, such as genetics, diet, and pre-existing health conditions, also play a role in the development of these disorders. The researchers acknowledge the need for randomized controlled trials to determine whether interventions aimed at reducing sedentary time during pregnancy can directly reduce the risk of hypertensive disorders.

The Path Forward: Research and Clinical Guidance

Dr. Whitaker and her team are planning further research to replicate these findings in larger and more diverse cohorts. They are also investigating the underlying biological mechanisms that may explain the link between movement behaviors and hypertensive disorders of pregnancy. Understanding these mechanisms could lead to the development of more targeted interventions.

The ultimate goal is to inform clinical guidelines and public health recommendations. Currently, guidelines generally recommend moderate-intensity exercise during pregnancy, but these findings suggest that focusing on reducing sedentary time and increasing light-intensity activity should also be prioritized. Healthcare providers can play a crucial role in counseling pregnant patients about the importance of incorporating more movement into their daily routines.

Ongoing Surveillance and Emerging Threats

Alongside research efforts, ongoing surveillance of hypertensive disorders of pregnancy is essential for monitoring trends and identifying potential risk factors. The Centers for Disease Control and Prevention (CDC) and other public health agencies track the incidence of these disorders and provide resources for healthcare providers and pregnant individuals. It’s also important to stay informed about any emerging threats or advisories related to maternal health.

What’s next? Dr. Whitaker emphasized the need for intervention studies to definitively determine whether reducing sedentary time during pregnancy can reduce the risk of developing a hypertensive disorder. These trials are essential for translating research findings into practical recommendations that can improve the health of mothers and babies.

Kara Whitaker, PhD, MPH, FAHA, can be reached at [email protected].