Articles (EN)

Edema during pregnancy: norm and anxiety

2026-05-27 12:00 Pregnancy
In short: Mild swelling of the legs in the second half of pregnancy is a physiological norm, occurring in 50-80% of women. Alarming signs: a sharp increase in swelling, swelling of the face and hands, high blood pressure, protein in the urine - these may be symptoms of preeclampsia that requires urgent care.

Why does edema occur during pregnancy?

Edema during pregnancy is a consequence of normal physiological changes. The volume of blood and fluid in the body during pregnancy increases by 40-50%. The growing uterus compresses the pelvic veins and the inferior vena cava, disrupting the outflow of venous blood from the legs. Under the influence of progesterone, the walls of blood vessels become more permeable, fluid passes more easily from vessels to tissues.
All this leads to fluid retention in the tissues - especially in the lower extremities and under the skin. Physiological edema is not excess water in the body, but a redistribution of fluid between compartments. Limiting drinking with such edema not only does not help, but can harm.

Physiological (normal) edema

Physiological edema during pregnancy has characteristic features:
They appear in the afternoon after a long stay on their feet.
They are localized in the lower legs, ankles and feet.
Disappear or decrease significantly after a night's sleep or rest with your legs elevated.
They increase gradually, there is no sharp deterioration.
They are not accompanied by high blood pressure, headache, visual disturbances.
Physiological edema is safe for mother and child and does not require drug treatment. In about 50-80% of pregnant women, they are present to some extent in the third trimester.

Pathological edema: when to sound the alarm

Edema becomes an alarming symptom if they:
They suddenly increase (an increase of more than 500 g per week or 2 kg in 3 days).
They spread to the face and hands (especially swelling of the face is a characteristic sign of preeclampsia).
They do not go away after a night's sleep.
They are combined with high blood pressure (BP ≥ 140/90 mm Hg).
They are combined with protein in the urine.
They are accompanied by headache, visual disturbances ("floaters", shroud), pain in the right hypochondrium.
The combination of edema with high blood pressure and protein in the urine is the classic triad of preeclampsia (late toxicosis). This is a life-threatening complication that requires immediate hospitalization.

How to reduce physiological edema

Rest with your legs raised. Lie down and place your feet on a pillow or bolster so that they are above the level of your heart. This improves venous outflow. Take such breaks several times a day for 15-20 minutes.
Compression knitwear. Compression stockings or socks of 1-2 compression classes are put on in the morning, without getting out of bed, and are worn during the day. They significantly reduce swelling and reduce the risk of thrombosis, especially with varicose veins and prolonged standing on their feet.
Moderate physical activity. Walking and swimming stimulate the work of the "muscle pump" in the legs, improving venous outflow. Standing for a long time or sitting with your legs down, on the contrary, increases swelling. For more information, see the article Sports and physical activity during pregnancy.
Drinking regimen. Contrary to intuition, there is no need to limit water during edema - it will not help. It is recommended to drink enough (1.5-2 liters per day), as dehydration causes the body to retain water more actively. Exclude carbonated drinks and sweet juices.
Salt. Excess salt in the diet increases fluid retention. It is recommended to limit the consumption of table salt to 5-6 g per day (about 1 teaspoon). Give up salty snacks, chips, canned food, ready-made sauces.
Sleeping position. Sleep on your left side – this reduces the pressure of the uterus on the inferior vena cava and improves venous outflow from the legs.
Comfortable shoes. Give up tight shoes, high heels and socks with a tight elastic band. Wear wide, comfortable shoes or slippers at home.

Diuretics during pregnancy: do they help?

Diuretics (diuretics) are not used for physiological edema of pregnancy and are contraindicated. They reduce the volume of circulating blood, which reduces placental blood flow and can cause fetal growth retardation. Diuretics are prescribed only for specific indications (severe preeclampsia, heart failure) and only under strict medical supervision.

Deep vein thrombosis: a rare but dangerous complication

Pregnancy increases the risk of deep vein thrombosis of the legs by 4-5 times. Signs: pain, redness and induration along the vein in the lower leg, a sharp increase in swelling of one leg (asymmetrical edema). Deep vein thrombosis requires immediate medical attention - it is dangerous with pulmonary embolism. In case of thrombosis, anticoagulant therapy is prescribed.

When to see a doctor

See your doctor right away if:
Swelling increases sharply or appears on the face and hands.
BP above 140/90 mm Hg.
Headache, visual disturbances, pain in the right hypochondrium appeared.
One leg is noticeably larger than the other and is painful when palpated (suspected thrombosis).
Shortness of breath at rest.

Frequently Asked Questions

Does edema affect the fetus?

Physiological edema itself does not affect the fetus. Pathological edema that accompanies preeclampsia is dangerous, but in this case, it is preeclampsia that poses a threat, and not edema as such.

Does herbal tea help with diuretic action during pregnancy?

Many herbs traditionally used as diuretics are unsafe during pregnancy. You should not use any herbal remedies without consulting a doctor.

Conclusion

Mild swelling of the legs in the second half of pregnancy is a normal phenomenon that occurs in most women. Compression stockings, rest with your legs elevated, moderate activity and salt restriction will help. Alarming signs - a sharp increase, swelling of the face, high blood pressure, protein in the urine - require immediate medical attention.

Bibliography

  1. ACOG Practice Bulletin No. 222. Gestational Hypertension and Preeclampsia. Obstet Gynecol. 2020. https://pubmed.ncbi.nlm.nih.gov/32443079/
  2. NICE Guideline NG133. Hypertension in pregnancy: diagnosis and management. 2019. https://www.nice.org.uk/guidance/ng133
  3. WHO. WHO recommendations for prevention and treatment of pre-eclampsia and eclampsia. WHO, 2011. https://www.who.int/publications/i/item/9789241548335
  4. Bates SM, et al. VTE, thrombophilia, antithrombotic therapy, and pregnancy. Chest. 2012;141(2 Suppl):e691S-e736S. https://pubmed.ncbi.nlm.nih.gov/22315276/
  5. Ministry of Health of the Russian Federation. Clinical guidelines: Preeclampsia. Eclampsia. Ministry of Health of the Russian Federation, 2021. https://cr.minzdrav.gov.ru/
This material is for informational purposes only and does not constitute medical advice and is not a substitute for medical advice. If a child's sleep is accompanied by alarming symptoms, a pronounced deterioration in health, problems with breathing, feeding or weight gain, it is necessary to consult a qualified medical specialist as soon as possible, and not rely only on information from the Internet.