Pregnant women who limit their sedentary time to eight hours or less per day and increase light physical activity to at least seven hours daily may reduce their risk of developing hypertensive disorders by nearly 30%, according to preliminary research presented at the American Heart Association's EPI|Lifestyle Scientific Sessions in Boston on March 19.
This finding is significant because high blood pressure during pregnancy can lead to serious health problems for both mothers and babies. The study suggests that everyday movement, rather than just structured exercise, could play a key role in lowering these risks.
Lead study author Kara Whitaker, Ph.D., M.P.H., FAHA, said, "Our study suggests that in the real world, where daily routines vary widely, it may actually be the balance of sitting time and light intensity movement across the entire day that matters most." She added, "This doesn't mean exercise isn't beneficial—rather, that when it comes to hypertensive disorders of pregnancy, everyday movement and limiting long periods of sitting may play a bigger role than we previously understood."
High blood pressure develops in up to 5%–10% of all pregnancies and is a leading cause of fetal and maternal disease and death. The researchers aimed to identify optimal patterns of behavior throughout pregnancy that are linked with the lowest risk for these conditions. Natalie A. Bello, M.D., M.P.H., an American Heart Association volunteer expert who was not involved with the study, said, "Both sedentary behavior and hypertension in pregnancy are increasingly common, and in non-pregnant individuals we know that physical activity is associated with reductions in blood pressure." Bello continued, "The researchers extend this to the pregnant population where nearly 20% of participants developed a hypertensive disorder of pregnancy. They saw incremental associations between more physical activity and lower risk of developing preeclampsia or gestational hypertension. It remains to be seen whether this association is causal, and future studies designed to increase physical activity and reduce sedentary behavior in pregnancy are needed."
The results support recommendations from the American Heart Association's Life Essential 8 for Pregnancy guidelines which encourage regular movement throughout the day along with healthy eating habits and monitoring health indicators such as cholesterol and blood pressure.
Whitaker concluded, "These findings have the potential to shift how we think about physical activity and sleep during pregnancy. Right now, there are no clear, quantitative guidelines for how much sitting or light intensity movement is healthiest during pregnancy, and our results provide early evidence that could help shape those recommendations in the future. Ultimately, this line of research could give patients and clinicians more practical, achievable ways to support healthier pregnancies."
The authors noted limitations including a participant group mostly composed of white women with higher education levels; therefore results may not apply broadly across different populations. Larger studies involving more diverse groups are needed for confirmation.
