Sitting Over 10 Hours a Day Raises Pregnancy Complication Risk

Replacing prolonged sitting with light daily movement during pregnancy was associated with healthier pregnancy outcomes.

Spending long hours sitting each day during pregnancy was associated with a higher risk of complications, while replacing some of that time with light movement could offer meaningful health benefits. An original investigation published in JAMA found that pregnant individuals who sat less, engaged in more light-intensity physical activity, and took more daily steps experienced fewer adverse pregnancy outcomes (1^✔ ✔Trusted Source
Adverse Pregnancy Outcomes and Sedentary Behavior, Light-Intensity Physical Activity, and Daily Steps

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Among 470 pregnant participants, the average sedentary time was 10.1 hours per day, with an average of 4.6 hours of light-intensity physical activity and 6,783 daily steps. Overall, 37% experienced an adverse pregnancy outcome, while 18.3% developed hypertensive disorders of pregnancy. The primary outcome included hypertensive disorders of pregnancy, gestational diabetes, preterm birth, and babies born small for gestational age. Participants with high sedentary time had an absolute risk of adverse pregnancy outcomes of 42.3%, compared with 19.0% among those with low sedentary time. Those with very high light-intensity physical activity had an absolute risk of 21.1%, compared with 40.3% among those with low activity. Participants with higher daily step counts also experienced fewer adverse pregnancy outcomes than those with the lowest step counts.

Pregnancy Activity Patterns and Pregnancy Complications

The investigation followed pregnant volunteers from early pregnancy through all three trimesters between 2021 and 2025.

Instead of relying on questionnaires, participants wore a thigh-mounted accelerometer that measured:

• Time spent sitting
• Light-intensity physical activity
• Daily step counts
• Activity patterns across pregnancy

Pregnancy outcomes were confirmed using medical records and physician review. Because activity was measured objectively rather than self-reported, the findings are considered more reliable than studies relying only on questionnaires.

Less Sitting Was Linked to Better Pregnancy Outcomes

Participants who spent the most time sitting each day were more than twice as likely to experience adverse pregnancy outcomes compared with those who spent the least time sitting.

The complications evaluated included:

• Hypertensive disorders of pregnancy
• Gestational diabetes
• Preterm birth
• Babies born small for gestational age

Interestingly, the associations remained even after accounting for moderate-to-vigorous physical activity and prepregnancy body mass index. This suggests that simply reducing prolonged sitting may have benefits beyond scheduled exercise sessions. The researchers estimated that replacing one hour of sitting each day with light-intensity physical activity was associated with a lower risk of adverse pregnancy outcomes.

Light-Intensity Physical Activity May Matter More Than Expected

The article highlights the importance of light-intensity physical activity, which includes everyday movement rather than structured workouts.

Someone working at a desk during pregnancy may benefit from regularly standing up, walking around the room, or completing routine household activities instead of remaining seated for long periods. Likewise, choosing to walk while making a phone call or taking short movement breaks throughout the day contributes to light physical activity.

Participants who accumulated the greatest amount of light-intensity movement experienced approximately half the risk of adverse pregnancy outcomes compared with those who were least active.

Daily Steps Were Also Associated With Lower Risk

Women in the highest daily step-count group experienced fewer adverse pregnancy outcomes than those in the lowest group.

Rather than focusing only on exercise sessions, the results suggest that overall daily movement throughout pregnancy may play an important role in supporting maternal health.

Why These Findings Matter for Everyday Pregnancy

Many people think pregnancy activity only refers to structured exercise. This investigation broadens that perspective by showing that ordinary movement throughout the day may also be associated with healthier pregnancy outcomes.

For someone balancing work, household responsibilities, and pregnancy, replacing some sitting time with gentle movement may feel more achievable than committing to vigorous exercise. The findings encourage a broader view of staying active during pregnancy without suggesting that intense workouts are necessary.

As Barone Gibbs and colleagues concluded, “Among pregnant individuals, sitting less with greater light-intensity movement and steps was associated with significantly lower risks of adverse pregnancy outcomes.”

Because this was an observational study, it cannot prove that prolonged sitting directly causes pregnancy complications. It also does not mean vigorous exercise is necessary. Instead, the findings suggest that replacing some sitting time with light movement may support healthier pregnancy outcomes.

If you’re pregnant and wondering how much daily movement is appropriate for you, discuss your usual activity patterns with your healthcare provider. Small changes that reduce prolonged sitting may become part of a healthy pregnancy plan when tailored to your individual needs.

Reference:

1. Adverse Pregnancy Outcomes and Sedentary Behavior, Light-Intensity Physical Activity, and Daily Steps – (https://jamanetwork.com/journals/jama/article-abstract/2849458)

Source-Medindia