Swelling in Pregnancy

Why swelling happens in pregnancy

• More fluid: blood volume rises by roughly 40% to 50% during pregnancy, and the body holds extra water.
• Pressure on veins: the growing uterus presses on the large vein (inferior vena cava) and pelvic veins, slowing blood returning from the legs.
• Hormones: pregnancy hormones relax vein walls and change how the kidneys handle salt and water.
• Lower protein levels in the blood make fluid leak more easily into tissues.

Swelling is often worse:

• late in the day
• in hot weather
• after standing or sitting for long periods
• with twins or more
• in the third trimester and the first days after birth

Normal swelling vs warning signs

Preeclampsia

Preeclampsia is a pregnancy condition with high blood pressure and signs of organ strain, usually after 20 weeks and sometimes up to 6 weeks after birth. Swelling alone does not mean preeclampsia, since most pregnant women swell, but sudden or severe swelling of the face and hands is a warning sign. Other symptoms:

• severe headache not relieved by acetaminophen (paracetamol)
• vision problems: blurring, flashing lights or spots
• pain just below the ribs, especially on the right
• nausea or vomiting in the second half of pregnancy
• sudden weight gain (more than about 2 lb or 1 kg in a week)
• shortness of breath

Many women with preeclampsia have no symptoms, which is why blood pressure and urine are checked at every prenatal visit. Severe forms include HELLP syndrome and eclampsia (seizures). Risk factors include a first pregnancy, preeclampsia in a previous pregnancy, chronic high blood pressure, diabetes, kidney disease, obesity, age over 35 and twins. Low-dose aspirin from early pregnancy is recommended for women at high risk, under medical supervision.

Blood clots (DVT)

Pregnancy and the 6 weeks after birth increase the risk of deep vein thrombosis. Suspect a clot if one leg is more swollen than the other, with calf or thigh pain, warmth, redness or heaviness. Left-leg clots are more common in pregnancy. A clot that travels to the lungs causes breathlessness and chest pain and is an emergency. Diagnosis is by ultrasound, and treatment is with heparin injections, which are safe in pregnancy.

Other causes of swelling

• Varicose veins in the legs or vulva
• Carpal tunnel syndrome: swollen wrists squeeze a nerve, causing numb, tingling fingers, especially at night
• Peripartum cardiomyopathy: a rare heart weakness late in pregnancy or after birth, with breathlessness, swelling and fatigue
• Kidney disease
• Cellulitis: a red, hot, painful patch of skin with fever

How to reduce swelling in pregnancy

• Put your feet up when sitting, ideally above hip level, for 20 minutes several times a day.
• Avoid standing or sitting still for long periods. Walk around and do ankle circles and foot pumps every hour.
• Lie on your left side when resting; this takes pressure off the large vein.
• Wear waist-high maternity compression stockings, put on in the morning before swelling builds.
• Wear comfortable, supportive shoes, and avoid tight socks, rings and watches.
• Stay cool, and try standing or walking in a pool, which reduces swelling through water pressure.
• Drink enough water. Restricting fluids does not help swelling.
• Stay active with walking, swimming or prenatal exercise.

Diuretics (water pills) are not used for normal pregnancy swelling.

After birth

Swelling can increase in the first few days after delivery as fluid shifts, particularly after IV fluids or a cesarean. It usually settles within 1 to 2 weeks. Preeclampsia can still develop after birth, so report severe headaches, vision changes or breathlessness promptly.

Frequently asked questions

Is swelling in pregnancy normal?

Yes. Mild swelling of the feet and ankles is very common, especially in the third trimester, at the end of the day and in hot weather. It is caused by extra fluid and pressure from the uterus on leg veins and usually improves with rest and elevation.

When should I worry about swelling in pregnancy?

Call your provider the same day for sudden swelling of your face, hands or feet, swelling of one leg with pain or redness, or swelling with a severe headache, vision changes, upper belly pain, vomiting or breathlessness. These can be signs of preeclampsia or a blood clot.

Does swelling mean preeclampsia?

Not on its own. Most pregnant women swell. Swelling becomes concerning when it is sudden, affects the face or hands, or comes with high blood pressure, headache, vision changes or upper belly pain. Blood pressure and urine checks are needed to diagnose preeclampsia.

How can I reduce swollen feet during pregnancy?

Elevate your feet, avoid standing or sitting still for long, move your ankles often, lie on your left side, wear maternity compression stockings, stay cool, and drink enough water. Comfortable shoes and avoiding tight bands around your ankles also help.

When does swelling start in pregnancy?

Some women notice mild swelling in the second trimester, but it is most common from around 27 weeks and peaks in the final weeks. Swelling usually resolves within 1 to 2 weeks after giving birth.