Activity restriction in pregnancy remains a common clinical recommendation for individuals at high risk for early delivery. However, medical evidence supporting this practice is surprisingly scarce. The AWARE study recently evaluated how movement levels impact pregnancy outcomes in patients with a short cervix. Additionally, this research highlights the potential dangers of limiting physical activity during the second trimester.
Findings from the AWARE Study
Researchers conducted this ancillary study among 120 participants between 16 and 24 weeks of gestation. Specifically, they used wrist accelerometers to monitor daily step counts until the time of delivery. The team compared outcomes between sedentary individuals and more active participants. Furthermore, researchers defined sedentary activity as taking fewer than 3,500 steps per day. Consequently, the primary outcome focused on the latency from enrollment to birth.
The results showed no significant difference in pregnancy latency between the two groups. However, sedentary participants delivered at a significantly earlier gestational age of 34.9 weeks. In contrast, those taking 3,500 or more steps delivered at an average of 37.7 weeks. Therefore, the data suggests that physical inactivity may negatively influence the timing of delivery.
Impact of Activity Restriction in Pregnancy
Clinicians often suggest activity restriction in pregnancy to prevent premature labor. Moreover, about 25% of study participants had already received such advice from their practitioners. Despite these common recommendations, the study found that sedentary behavior increased the likelihood of delivery before 34 weeks. Specifically, nearly 47% of sedentary individuals delivered before this milestone compared to only 18% of active individuals. Therefore, prescribing bed rest might inadvertently harm patients by reducing their daily activity below safe thresholds.
Medical professionals should discuss these findings with their patients to encourage safe movement. This evidence aligns with international guidelines that caution against routine activity restriction for preventing preterm birth. Maintaining moderate activity levels appears far safer than immobilization for patients with a short cervix. Additionally, Indian cohort data supports the finding that sedentary behavior correlates with higher preterm birth rates.
Frequently Asked Questions
Q1: Does activity restriction help prevent preterm birth?
No, the AWARE study showed no statistically significant difference in pregnancy latency for those placed on activity restriction.
Q2: What are the risks of taking fewer than 3,500 steps per day?
Taking fewer than 3,500 steps per day is associated with an increased risk of delivering before 34 weeks and a shorter overall gestational age.
Q3: Is bed rest recommended for a short cervix?
Current evidence suggests that bed rest and sedentary behavior may increase the risk of early delivery. Therefore, clinicians should avoid routine activity restriction for these patients.
References
- Sciscione AC et al. Activity Restriction in Pregnancy and the Risk of Early Delivery: The AWARE Study. Obstet Gynecol. 2026 Feb 19. doi: 10.1097/AOG.0000000000006225. PMID: 41712929.
- American College of Obstetricians and Gynecologists. ACOG Committee Opinion No. 804: Physical Activity and Exercise During Pregnancy and the Postpartum Period. Obstet Gynecol. 2020.
- Girish N, et al. Association of physical activity level during pregnancy with preterm birth and infant adiposity: longitudinal analysis from the MAASTHI cohort, India. BMC Pregnancy and Childbirth. 2023.