A study presented at the American Heart Association's EPI|Lifestyle Scientific Sessions 2026 suggests that pregnant women can reduce their risk of developing hypertensive disorders by nearly 30% by limiting sedentary time to no more than eight hours a day and increasing light physical activity to at least seven hours a day. The research, involving 470 women across three U.S. cities, measured sedentary behavior, sleep, and physical activity across a 7-day, 24-hour timeframe during each trimester.
According to the study, the amount of time spent sitting and doing light physical activity were the main predictors of developing blood pressure-related conditions of pregnancy, such as gestational hypertension and preeclampsia. Women who limited sitting to about eight hours daily, engaged in at least seven hours of light physical activity, 22 minutes of higher intensity activity, and nine hours of sleep had a 30% lower risk of developing these conditions.
“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,” said lead author Kara Whitaker, Ph.D., M.P.H., FAHA, an associate professor at the University of Iowa. “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 study found that the lowest-risk daily pattern included about six hours of sitting, nearly eight hours of light physical activity, four minutes of higher-intensity activity, and roughly 10 hours of rest. This pattern was linked to an 8% chance of developing hypertensive disorders, compared to 16.9% for typical patterns.
The findings align with the American Heart Association’s Life Essential 8 for Pregnancy recommendations, which encourage movement throughout the day, adequate sleep, and blood pressure monitoring. The researchers note that more studies are needed to test whether interventions to reduce sitting and increase light activity can causally lower risk.
The study had limitations, including a predominantly white, higher-education sample, so results may not generalize to all populations. Further research with diverse groups is needed to confirm these findings.
