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Swollen Feet During Pregnancy: Why It Happens & What To Do

There comes a time in pregnancy when you can no longer see your own feet. And, unfortunately, there may also come a time when you wouldn’t want to — because they suddenly look and feel like water balloons. 

For most pregnant women, carrying extra fluid in the legs and feet is, sadly, all too normal. In fact, leg and foot edema occurs in about 80% of all pregnancies (Yanagisawa). In some cases, swollen feet may indicate a dangerous underlying condition, such as preeclampsia or a deep vein blood clot. More commonly, swelling results from pressure on the vein valves and walls. 

At Comrad, we make socks that help to improve circulation and reduce pressure on your veins, so you can avoid potato feet (what we like to call swollen feet) throughout your pregnancy. 

No matter the cause, swollen feet can be uncomfortable. By the time women reach the third trimester of pregnancy, they're often searching for ways to reduce fluid retention and improve venous return. 

Luckily, we have the perfect blend of style and comfort to stop feet from swelling during pregnancy.

How Much Do Feet Swell?

First of all, it's important to understand how much your feet swell during pregnancy. In one study published in The Journal of Bone and Joint Surgery, researchers set out to understand this phenomenon. They noted, "During pregnancy, there was a statistically significant increase in the volume of the feet that was equivalent, on the average, to 8.5 per cent of the volume of each foot” (Alvarez 274). This comparison of early and late pregnancy measurements showed that the women in the study gained considerable volume. 

Even after giving birth, the study participants did not experience a return to pre-pregnancy volumes. The researchers explained, "At the eight-week postpartum visit, the mean volume had decreased by only 1.20 per cent compared with the volume at thirty-five weeks of gestation" (274). The researchers attributed this long-lasting increase in volume to an accumulation of either extracellular fluid or soft tissue.

Another study found that women demonstrated an increase in foot length, width, and surface area between the 20th to the 38th week of pregnancy. During the same time period, the arch of the foot fell by an average of over 24% (Chiou Abstract). As the uterus grows, this evidence suggests that a pregnant woman's feet may be growing, too. Plus, these measurements indicate that the weight gain may impact additional structures in the feet beyond the soft tissue, including the arch.

So, if you feel like your feet have been getting larger during pregnancy, and need more support, the scientific evidence supports your observation.

Why Do Feet Swell During Pregnancy?

A number of different medical conditions can cause swelling, so it's important to watch out for symptoms that could indicate health problems. When in doubt, seek advice from a healthcare provider. 

Chronic Venous Insufficiency (CVI)

During pregnancy, the growing uterus can put pressure on the vena cava, the large vein that carries deoxygenated blood to the heart. In addition, hormonal changes make your veins more likely to distend, and most women show an increase in vein diameter over the course of their pregnancies (Cornu-Thenard and Boivin 138). 

Because of these risk factors, which increase pressure on the vascular walls and valves, pregnant women are more likely to develop venous disease during pregnancy. 

Approximately 15% of pregnant women experience varicose veins, bulging blue or purple veins that appear just under the skin's surface (139). Varicose veins form when the one-way valves inside the veins fail. Venous reflux, or the back-flow of blood through faulty valves, inhibits the healthy return of blood from the lower extremities to the heart. 

Blood pools in the lower legs and feet, and spider veins, varicose veins, swelling, and ulcers can result. 

Deep Vein Thrombosis (DVT)

Swelling can also be a sign of deep vein thrombosis, which can lead to life-threatening complications for both men and women. According to the Centers for Disease Control and Prevention, pregnancy increases the risk of developing a blood clot fivefold. When a blood clot (thrombus) forms in the deep vein, it can break off and travel through the bloodstream. In rare cases, a clot can cause a fatal blockage in the lung, called a pulmonary embolism. 

Usually, swelling from DVT only affects one leg. Unlike typical swelling during pregnancy, DVT may be accompanied by severe discomfort, heaviness, and unusual skin sensation. If you think you could be exhibiting the symptoms of a deep vein blood clot, you should seek immediate medical attention. 


Edema in the face, hands, and feet can be a minor symptom of preeclampsia, a dangerous condition associated with high blood pressure during or after pregnancy. The onset of preeclampsia typically occurs after the 20th week of pregnancy, so swelling in the early stages of pregnancy is unlikely to be caused by this disease. Swelling does not occur for all patients with preeclampsia. 

Other symptoms of preeclampsia include high blood pressure, protein in the urine, severe headaches, changes in vision, abdominal pain, nausea, shortness of breath, etc. 

If you experience sudden swelling in the extremities after the 20th week of pregnancy, be sure to inform your doctor. It can be difficult to differentiate normal swelling from a sign of preeclampsia, so your doctor may want to run tests to determine the cause of your swelling, especially if you display additional symptoms. 

Ways to Reduce Edema

Wearing compression garments, either socks or stockings, is one of the first-line treatments for swollen legs and feet during pregnancy. Studies have shown that graduated compression hosiery improves venous emptying and reduces subjective reports of discomfort and pain (Nilsson Abstract). 

In addition, compression causes a measurable improvement in maternal and fetal circulation (Weber Abstract). Compression socks and stockings also reduce the risk of DVT during pregnancy. England's National Health Service advises pregnant women that wearing prescribed compression stockings is an important way to assist circulation in the legs and avoid DVT. 

French researchers Cornu-Thenard and Boivin agree, writing, "The wearing of medical compression therapy is recommended for the duration of the pregnancy and for 6 weeks after the birth" (141). They also recommend garments with a compression strength of 15-20 mmHg for the prevention of edema and 20-30 mmHg for the treatment of edema. 

In addition to wearing compression socks, there are other steps you can take to reduce swelling in your feet.

Techniques include:

  • Elevating your legs.
  • Stretching your ankles and calf muscles.
  • Sleeping on your left side to take pressure off the inferior vena cava.
  • Exercising regularly, especially with low-impact activities.
  • Swimming, floating, or standing in a pool, since water pressure may help to reduce swelling.
  • Wearing loose-fitting clothing.
  • Getting a foot massage or reflexology treatment.
  • Reducing your consumption of sodium.
  • Drinking plenty of water.

         (Tobah, "Edema")

Remember, if you experience swelling alongside other symptoms, such as difficulty breathing or chest pain, you should consult a doctor right away. Swelling is a normal part of pregnancy, but it can also be a sign of preeclampsia or DVT. Anytime you have a sudden increase in swelling, be sure to communicate with your doctor. 

To prevent and treat mild swelling, be sure to check out our 15-25 mmHg compression socks. Read more about how we’ve designed Comrad socks to make pregnancy a bit more comfortable


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