Physical Activity and Preterm Labor Risk
Mar 24, 2025
Rita Singha
Pregnancy Health
Regular physical activity during pregnancy can reduce the risk of preterm labor by up to 14% and early preterm birth by as much as 38%. Staying active improves blood flow, reduces inflammation, and supports a healthier pregnancy. Key findings from studies in 2024 and 2025 highlight that even modest exercise - like walking or prenatal yoga - can significantly lower risks for both mother and baby.
Key Takeaways:
Women with moderate activity levels have a lower risk of preterm birth compared to those with very low activity.
Exercise routines of 2–4 hours per week are most effective.
Activities like swimming, walking, and prenatal yoga are safe and recommended.
High-risk pregnancies may require tailored plans, but bed rest is no longer the default advice.
Safety precautions include avoiding high-impact sports, lying flat after 16 weeks, and overheating.
Quick Tips:
Aim for 150 minutes of moderate-intensity exercise per week (e.g., 30 minutes, 5 days a week).
Use the "talk test" to ensure intensity is safe - if you can talk comfortably, you're on track.
Consult your doctor before starting or adjusting your routine, especially if you have complications.
Staying active during pregnancy isn’t just safe - it’s a smart way to support your health and your baby’s development.
Research Findings on Physical Activity and Preterm Labor Risk
Benefits of Moderate Physical Activity
Research from 2024 and 2025 highlights a clear connection between moderate physical activity during pregnancy and a reduced risk of preterm labor. A meta-analysis covering 21 cohort studies and 20 randomized trials, which included 171,595 pregnant participants, found that higher levels of leisure time physical activity were linked to a 14% decrease in the relative risk of preterm birth.
Even modest increases in activity made a difference. For instance, adding just 3 hours of leisure physical activity per week was tied to a 10% lower risk of preterm birth. The most significant benefits were seen in those who engaged in 2–4 hours of physical activity weekly. These findings underline how even small, consistent efforts can influence outcomes.
A population-based study from Slovenia, published in June 2025, examined 190,331 singleton pregnancies and reported similar results. Regular physical activity - defined as engaging in any form of exercise at least twice a week throughout pregnancy - was associated with reduced odds of preterm birth. The adjusted odds ratio was 0.658 for births before 37 weeks and 0.393 for births before 32 weeks. This suggests that maintaining a consistent routine matters more than the intensity or type of activity.
Activity Type, Duration, and Timing Effects
The benefits of physical activity during pregnancy appear to depend more on consistency and duration than on the specific type of exercise. A 2024 study in JAMA Network Open followed 1,427 women with gestational diabetes and found that every additional 30 minutes of moderate-to-vigorous physical activity (MVPA) per day lowered the odds of preterm birth, with the risk plateauing around 74 minutes per day.
Interestingly, a "weekend warrior" approach - where physical activity is concentrated into fewer days - offered similar benefits to regular activity. Compared to inactive individuals (less than 30 minutes of MVPA daily), the odds ratios for preterm birth were 0.24 for those regularly active and 0.23 for weekend warriors.
On the flip side, extremely low activity levels carry notable risks. A Japanese study involving 86,516 participants showed that women in the "very low" activity group (0–1.1 METs-hours per week) faced a 16% higher risk of preterm delivery and a 38% higher risk of early preterm delivery (before 32 weeks) compared to those with moderate activity levels. Similarly, data from the MAASTHI cohort in India, published in May 2025, revealed that sedentary behavior during pregnancy was associated with a 1.43 times higher likelihood of preterm birth.
Physical Activity in High-Risk Pregnancies
The link between physical activity and preterm birth becomes more nuanced in high-risk pregnancies. A study involving 6,501 women found that the protective effects of exercise were mostly seen in those without pregnancy complications. For women with complications, the adjusted odds ratio for preterm birth associated with exercise was 0.87 - a result that was not statistically significant.
However, there were positive findings for women with gestational diabetes. The 2024 JAMA Network Open study showed that MVPA reduced the risk of preterm birth in this group. Additionally, the 2025 Slovenian study found that physically active women with gestational diabetes were less likely to need insulin, with an adjusted odds ratio of 0.768.
A systematic review of nine studies involving 3,173 women with high-risk pregnancies found no significant difference in preterm birth rates between those who maintained physical activity and those prescribed bed rest or activity restriction. This challenges the long-standing practice of recommending bed rest for high-risk pregnancies - a strategy historically used by 90–95% of maternal healthcare professionals. Instead, these findings suggest that staying moderately active, even in high-risk situations, can help offset the negative physical and psychological effects of prolonged inactivity. Tailored activity plans may be a better approach for managing high-risk pregnancies.
How can you prevent preterm labour? | Dr Sheetal Dayal
How Physical Activity Reduces Preterm Labor Risk
Moderate exercise during pregnancy brings about changes that significantly support a healthy pregnancy and help reduce the risk of preterm labor. Let’s explore how staying active works to protect both mother and baby.
Improved Blood Flow and Hormonal Regulation
Physical activity enhances blood flow to the uterus and placenta, ensuring that nutrients and oxygen reach the baby more efficiently - key factors in minimizing the risk of preterm labor. Exercise also helps reduce stress levels, which in turn can lower inflammation. A 2017 systematic review revealed that women engaging in aerobic exercise for 30–60 minutes, 2–7 times per week, showed a reduced likelihood of developing gestational hypertensive disorders compared to those with more sedentary lifestyles.
In addition to better circulation, regular exercise promotes hormonal balance, which plays a vital role in maintaining a healthy pregnancy.
Reduced Inflammation and Strengthened Muscles
Exercise has an anti-inflammatory effect by lowering levels of key biomarkers such as TNF-α, IL-6, IL-1β, and CRP - factors often linked to preterm labor. Pregnant women who achieve the recommended 150 minutes of activity per week have been shown to exhibit reduced CRP levels in both maternal and umbilical cord blood compared to inactive women.
Supervised exercise programs that combine aerobic and resistance training are particularly effective. These routines have been associated with reduced TNF-α concentrations, a more controlled increase in IL-1β during late pregnancy, and lower levels of IL-6 and TNF-α in umbilical cord blood. Additionally, managing gestational weight gain through exercise helps mitigate inflammation caused by excess weight, which can otherwise increase the risk of preterm birth.
Beyond its anti-inflammatory benefits, regular physical activity strengthens vital muscle groups. Light exercises during the third trimester, for instance, improve pelvic floor muscle strength, enhance blood flow, and help lower the risk of preterm labor. Jin Zhang and colleagues highlight this point:
"A longer time of relaxed exercise activities in the 3rd trimester may help pregnant women relieve tension, promote blood circulation, increase pelvic floor muscle strength."
Strengthening core muscles also plays a big role in reducing back pain, supporting the growing uterus, and maintaining stability. Improved core strength, better body composition, and greater flexibility work together to create a safer environment for carrying the baby to full term. These combined benefits illustrate how moderate physical activity contributes to healthier, full-term pregnancies.
Physical Activity Guidelines for Pregnant Women
Having clear physical activity guidelines during pregnancy ensures you can enjoy the benefits of exercise while keeping yourself and your baby safe. These recommendations align with how exercise improves blood flow, reduces inflammation, and supports overall well-being during pregnancy.
General Activity Recommendations
Pregnant women are encouraged to get at least 150 minutes of moderate-intensity aerobic activity each week. That’s about 30 minutes on most days, but you can split this into shorter 10-minute sessions if that fits your schedule better. For those with gestational diabetes, studies suggest that more than 74 minutes of moderate-to-vigorous activity daily can significantly reduce the risk of preterm birth.
Some great options for exercise include brisk walking, swimming, stationary biking, prenatal yoga, Pilates, low-impact aerobics, and strength training. The goal is to maintain a moderate intensity - use the talk test (you should be able to hold a conversation while exercising) or aim for a Borg Rating of Perceived Exertion (RPE) of 13-14.
Different medical organizations offer slightly varied guidelines, but they all stress consistency. For instance, the American College of Obstetricians and Gynecologists recommends 30-60 minutes per session on at least 3-4 days a week, while the Royal Australian and New Zealand College suggests 150-300 minutes spread across the week.
If you didn’t exercise regularly before pregnancy, start slow with low-intensity activities like gentle walking or swimming, and gradually increase the duration or intensity. If you were already active, you can usually continue your routine with some adjustments as your pregnancy progresses.
Safety Precautions and Restrictions
While exercise is beneficial, it’s crucial to prioritize safety for both you and your baby.
Before beginning any exercise program, talk to your healthcare provider during your first prenatal visit. A medical evaluation will confirm whether it’s safe for you to exercise.
Absolute contraindications to exercise include conditions such as active preterm labor, vaginal bleeding, ruptured membranes, cervical insufficiency or cerclage, gestational hypertension or preeclampsia, placenta previa after 26 weeks, severe anemia, or certain heart and lung conditions.
As your pregnancy advances, certain activities and positions should be avoided. After the first trimester (around 16-20 weeks), steer clear of exercises that require lying flat on your back for extended periods, as the growing uterus can compress major blood vessels and reduce blood flow to your baby.
Some activities are simply too risky and should be avoided entirely, including:
Sports with a high risk of falls like horseback riding, downhill skiing, gymnastics, or skating.
Contact sports where you might be hit in the belly, such as ice hockey, boxing, soccer, or basketball.
Activities involving pressure changes, like scuba diving and skydiving.
Environmental factors also matter. Avoid exercising at altitudes above 6,000 feet unless you’re already acclimated to that elevation, as it can reduce oxygen delivery to your baby. Stay away from hot, humid conditions and activities that raise your body temperature significantly, like Bikram yoga.
Be alert to warning signs that signal you should stop exercising and seek medical attention. These include vaginal bleeding or fluid leakage, chest pain, a racing heartbeat, difficulty breathing, dizziness, headaches, muscle weakness, trouble walking, pain or swelling in your lower legs, regular painful contractions, or reduced fetal movement.
Stay hydrated by drinking plenty of water before, during, and after exercise. Wear comfortable and supportive athletic clothing, and be ready to adjust your routine as your body changes. For instance, what feels comfortable in your first trimester may need modifications in your third due to shifts in balance, weight, and joint flexibility.
If you have a condition like gestational diabetes, take extra precautions. This might include eating enough before exercising to avoid low blood sugar or adjusting insulin doses under the guidance of your healthcare provider.
Expert-Guided Support Through Rita's Pregnancy 101
Having professional guidance during pregnancy can make a world of difference, especially when it comes to staying active safely. Expert-led programs like those offered by Rita's Pregnancy 101 are designed to help expectant mothers maintain a healthy level of activity tailored to each stage of pregnancy. Here’s how they do it.
Prenatal Yoga and Meditation Classes
Rita's Pregnancy 101 specializes in prenatal yoga and meditation sessions that adapt to the unique changes your body goes through during pregnancy. With guidance from six certified instructors, these classes ensure you’re doing exercises that are safe and beneficial for both you and your baby.
Prenatal yoga has been shown to lead to better delivery outcomes, including more vaginal births and fewer cesarean sections. Research also highlights that yoga can reduce the likelihood of low birth weight, with significantly fewer cases reported among mothers who practiced yoga during pregnancy.
"Joining was the best decision I made. The yoga and meditation sessions were a game changer for my pregnancy." - Priya Mehta, Rita's Pregnancy 101 Testimonial
The combination of yoga and meditation in these classes doesn’t just focus on physical fitness - it also addresses stress management. Since high stress and inflammation can increase the risk of preterm labor, the meditation component helps regulate stress hormones and supports a balanced hormonal environment, contributing to a healthier pregnancy.
Trimester-Specific Activity Guidance
One of the trickiest parts of staying active during pregnancy is knowing how to adjust your routine as your body changes. Rita's Pregnancy 101 makes this easier by offering trimester-specific guidance tailored to each phase of pregnancy.
Their "Fit Pregnancy" program integrates yoga, walking plans, and diet recommendations that evolve as your pregnancy progresses. For instance, what works in the first trimester might need to be adjusted in the third trimester as your energy levels shift and your balance changes.
"From yoga to diet sessions, they covered it all. I highly recommend it to any expecting mom." - Shweta Patel, Rita's Pregnancy 101 Testimonial
This tailored approach ensures you know when to increase or decrease activity intensity, modify exercises, or avoid certain movements altogether. It’s all about helping you stay active in a way that feels right for your body while reducing risks like preterm labor.
Ongoing Online Support for Expectant Mothers
Consistency is key when it comes to staying active during pregnancy, and that’s where ongoing support becomes essential. Rita's Pregnancy 101 offers continuous online support through live sessions and interactive resources, creating a supportive environment for expectant mothers.
With over 5,000 satisfied mothers and an impressive 4.8 out of 5 rating from 306 reviews, the platform also fosters a sense of community. Peer support, combined with professional guidance, strengthens the benefits of staying active, which is crucial for reducing preterm labor risks.
"The guidance and support I received made my pregnancy journey so much easier and stress-free." - Aarti Joshi, Rita's Pregnancy 101 Testimonial
The online format makes it convenient to participate without worrying about transportation or scheduling conflicts. Live sessions allow for real-time feedback, so you can ensure your form and technique are safe and effective.
For those concerned about affordability, Rita's Pregnancy 101 offers a budget-friendly option at $67 per month, along with a one-week free trial to experience the program firsthand. This makes expert guidance accessible without financial strain.
"These classes helped me stay fit and calm throughout my pregnancy. I felt prepared and supported every step of the way." - Neha Shah, Rita's Pregnancy 101 Testimonial
Summary: Physical Activity and Preterm Labor Prevention
Research indicates that regular physical activity can lower the risk of preterm birth by 10–14%, with 2–4 hours of weekly leisure exercise providing even more protection.
Recent studies reveal that exercising at least twice a week can reduce the likelihood of delivering before 37 weeks by over 34% and early preterm births by as much as 60%. Additional data suggests an overall risk reduction of around 18%. These findings highlight not only the role of exercise in preventing preterm births but also its positive effects on broader pregnancy outcomes.
The benefits of staying active during pregnancy go beyond preterm birth prevention. Regular exercise can help decrease the risks of conditions like preeclampsia, gestational hypertension, pelvic girdle pain, and gestational diabetes requiring insulin. Among overweight and obese pregnant women, aerobic activity has been linked to about a 38% reduction in preterm birth rates. These advantages are tied to improved circulation, hormonal balance, and reduced inflammation - factors discussed earlier.
To ensure these benefits are achieved safely, professional guidance is key. Healthcare providers evaluate individual health needs, design tailored exercise plans, and address common concerns about physical activity during pregnancy. As the ACOG Committee on Obstetric Practice states:
"A thorough clinical evaluation should be conducted before recommending an exercise program to ensure that a patient does not have a medical reason to avoid exercise."
Evidence strongly supports encouraging pregnant women to stay active under proper supervision. Current recommendations advise against restricting activity. Dr. Beth Leong Pineles, a maternal-medicine specialist at Pennsylvania Hospital, reinforces this, noting:
"We really don't see any benefit of activity restriction. We have several national guidelines about exercise and physical activity and pregnancy, and all recommend against bedrest and recommend against routine activity restriction."
Staying active is not only safe but also an effective way to reduce the risk of preterm labor while promoting better health for both mother and baby.
FAQs
What are some safe and effective physical activities during pregnancy to help lower the risk of preterm labor?
Engaging in low-impact exercises like brisk walking, swimming, or gentle water workouts can be a great choice for pregnant women. These activities are gentle on the joints and promote overall well-being without putting unnecessary stress on the body.
Moderate-intensity workouts, particularly during the first and second trimesters, may help lower the risk of preterm labor. Starting with shorter, less intense sessions and gradually increasing the duration is a smart way to ease into a routine. However, it’s essential to check with your healthcare provider before starting or adjusting any exercise plan to ensure it’s safe and suitable for your pregnancy.
Can regular exercise during pregnancy help reduce the risk of preterm labor, and what are the key benefits for the mother and baby?
Regular exercise during pregnancy can play a key role in reducing the risk of preterm labor by promoting overall maternal health and ensuring a stable environment for the baby’s growth. Staying active can help lower the chances of complications like gestational diabetes, high blood pressure, and excessive weight gain - factors often associated with preterm birth.
On a physical level, exercise strengthens cardiovascular health, eases back and pelvic discomfort, and boosts energy levels. These benefits not only improve the mother’s quality of life but also support the baby’s development, making physical activity a valuable part of a healthy pregnancy. Always check with your healthcare provider before starting or adjusting your exercise routine.
What precautions should pregnant women take when exercising to ensure their safety and their baby’s health?
Pregnant women should steer clear of physical activity if they have certain medical conditions, including cervical complications, placental issues, uncontrolled high blood pressure, heart disease, leaking amniotic fluid, or a history of preterm labor. Conditions like anemia, preeclampsia, persistent bleeding, or carrying multiples may also call for extra care.
Always check with a healthcare provider before beginning or continuing any exercise routine during pregnancy. They can assess your health and pregnancy needs to recommend safe activities tailored to you.