Skipping regular walks during pregnancy raises your risk of several complications, from gestational diabetes and excessive weight gain to increased anxiety and worsening back pain. The World Health Organization, the American College of Obstetricians and Gynecologists, and Canadian guidelines all converge on the same target: at least 150 minutes per week of moderate-intensity activity, which translates to roughly 30 minutes of brisk walking most days. Falling well short of that threshold doesn’t guarantee problems, but it shifts the odds in ways that matter for both you and your baby.
Higher Risk of Gestational Diabetes
This is one of the most well-documented consequences of a sedentary pregnancy. Walking and other moderate activity help your muscles pull glucose from your bloodstream, keeping blood sugar levels stable as your body deals with the insulin resistance that naturally increases in the second and third trimesters. Without that regular movement, glucose builds up more easily.
Research published in the Indian Journal of Endocrinology and Metabolism found that pregnant women with low overall physical activity levels had roughly seven times the odds of developing gestational diabetes compared to more active women. The risk reduction from staying active ranges widely across studies, from 10% to as high as 90%, but the direction is consistent: more movement means lower risk. Gestational diabetes isn’t just a temporary inconvenience. It increases the chance of a larger-than-average baby, which can complicate delivery, and it raises your own risk of developing type 2 diabetes later in life.
Excessive Weight Gain
Pregnancy requires weight gain, but the amount matters. The Institute of Medicine guidelines set target ranges based on your pre-pregnancy weight: 25 to 35 pounds for normal weight, 15 to 25 for overweight, and 11 to 20 for obese. Gaining beyond those ranges is classified as excessive gestational weight gain, and physical inactivity is one of the primary drivers.
Excessive weight gain during pregnancy is linked to a cascade of problems: gestational hypertension, preeclampsia, cesarean delivery, and babies born large for gestational age. Those larger babies face higher rates of neonatal intensive care admission and are more likely to develop childhood obesity. The CDC notes that sedentary behavior, alongside unhealthy eating patterns and poor sleep, consistently shows up as a contributing factor in studies of excessive gestational weight gain.
Blood Clot Risk Increases
Pregnancy already puts you in a state where blood clots form more easily. Your blood becomes more prone to clotting (a protective mechanism against hemorrhage during delivery), your growing uterus presses on pelvic veins, and hormonal changes relax vein walls. By weeks 25 to 29, blood flow velocity in the legs drops by about 50%. You’re up to five times more likely to develop a deep vein thrombosis (DVT) during pregnancy than when you’re not pregnant.
Immobility compounds all of this. Clinical risk scoring systems for blood clots in pregnancy assign extra points to bed rest and immobilization, placing it alongside factors like personal clot history and obesity. Walking counteracts venous stasis by activating the calf muscles, which act as a pump to push blood back toward the heart. Without that regular pumping action, blood pools in the lower legs, and the risk of a clot forming rises further on top of the already elevated baseline. The absolute risk remains relatively low for most women (roughly 1 in 1,000 deliveries), but a DVT during pregnancy is a serious event that can lead to a pulmonary embolism.
Worse Back Pain and Physical Discomfort
It might seem logical that resting more would help with pregnancy aches, but the opposite tends to be true. A study of Portuguese pregnant women found a significant positive association between physical inactivity and higher functional disability from lower back pain. Women with severe back-related disability showed a moderate correlation with sedentary behavior specifically, meaning the more inactive they were, the worse their pain interfered with daily life.
This makes sense biomechanically. As your center of gravity shifts forward with a growing belly, the muscles supporting your spine need to work harder. Regular walking strengthens those muscles and improves circulation to the tissues around your spine. Sustained sitting or lying down, on the other hand, allows those muscles to weaken while also contributing to stiffness. Swelling in the legs and feet, another common pregnancy complaint, also worsens with prolonged inactivity because fluid pools in the lower extremities without the muscle contractions that help push it back into circulation.
More Anxiety and Stress
Walking during pregnancy has a measurable effect on mental health, and skipping it means missing out on that benefit. A study of women in their third trimester found that higher levels of walking were significantly associated with lower symptoms of generalized anxiety and perceived stress. Interestingly, even slow walking showed benefits across all mental health measures studied, including depression, generalized anxiety, perceived stress, and pregnancy-specific anxiety.
The effect sizes were small, meaning walking alone won’t resolve serious prenatal depression or anxiety. But the consistency of the finding across multiple mental health measures suggests that regular movement provides a genuine mood buffer during a period when hormonal shifts, sleep disruption, and life changes are already taxing your emotional reserves. Removing that buffer by staying sedentary leaves you more vulnerable to the psychological strain that pregnancy naturally brings.
Effects on Your Baby’s Heart Development
Your activity level during pregnancy appears to influence how your baby’s cardiovascular system develops. Research has shown that regular maternal exercise is associated with lower fetal resting heart rate and increased heart rate variability, both of which are markers of a healthy, well-developed autonomic nervous system. This mirrors what happens in adults who exercise regularly: their hearts become more efficient and beat more slowly at rest.
The fetal heart rate response appears to be dose-dependent, meaning more consistent maternal exercise produces a stronger training effect on the baby’s heart. Fetuses of regularly active mothers also showed faster heart rate recovery after the mother exercised, another sign of cardiovascular fitness. While these differences don’t necessarily mean sedentary mothers will have unhealthy babies, they do suggest that walking and other moderate activity give your baby’s heart an early developmental advantage.
How Much Walking You Actually Need
The global consensus is 150 minutes per week of moderate-intensity aerobic activity. For walking, “moderate intensity” means brisk enough that you’re slightly out of breath but can still hold a conversation. A simple benchmark: about 30 minutes a day, covering roughly four to five kilometers, on most days of the week. You don’t need to hit this all at once. Three 10-minute walks spread throughout the day count just as much.
If you’ve been inactive, the recommendation is to build up gradually rather than jumping to 30 minutes immediately. Even starting with short, slow walks provides some benefit, as the research on slow walking and mental health demonstrates. The goal is consistency over intensity.
When Walking Isn’t Recommended
There are specific medical conditions where exercise during pregnancy, including walking, is restricted. These absolute contraindications are agreed upon across guidelines from multiple countries and include persistent vaginal bleeding in the second or third trimester, cervical insufficiency or cerclage, preeclampsia, premature labor or contractions, premature rupture of membranes, serious cardiovascular or respiratory disease, and triplet or higher-order pregnancies. Placenta previa with bleeding is also on the list.
Notably, none of the major international guidelines provide specific criteria for prescribing bed rest, despite it being commonly recommended. The guidelines are designed for women with normal, uncomplicated pregnancies. If you have a high-risk condition, your activity level is a conversation to have with your care provider, but for the vast majority of pregnant women, walking is not only safe but actively protective.