Merck Manual

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Lower-Extremity Edema During Late Pregnancy


Geeta K. Swamy

, MD, Duke University Medical Center;

R. Phillip Heine

, MD, Duke University Medical Center

Last full review/revision Jul 2018| Content last modified Aug 2018
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Edema is common during late pregnancy. It typically involves the lower extremities but occasionally appears as swelling or puffiness in the face or hands.


The most common cause of edema in pregnancy is

  • Physiologic edema

Physiologic edema results from hormone-induced sodium retention. Edema may also occur when the enlarged uterus intermittently compresses the inferior vena cava during recumbency, obstructing outflow from both femoral veins.

Pathologic causes of edema are less common but often dangerous. They include

DVT is more common during pregnancy because pregnancy is a hypercoagulable state, and women may be less mobile.

Preeclampsia results from pregnancy-induced hypertension; however, not all women with preeclampsia develop edema.

When extensive, cellulitis, which usually causes focal erythema, may resemble general edema.


Some Causes of Edema During Late Pregnancy


Suggestive Findings

Diagnostic Approach

Physiologic edema

Symmetric, bilateral leg edema that lessens with recumbency

Diagnosis of exclusion


Tender unilateral swelling of a leg or calf, erythema, and warmth

Sometimes presence of risk factors for DVT

d-Dimer testing and/or lower-extremity duplex ultrasonography


Hypertension and proteinuria, with or without significant nondependent edema (eg, in face or hands), which, when present, is not red, warm, or tender

Sometimes presence of risk factors for preeclampsia

When preeclampsia is severe, possibly additional symptoms of headache; pain in the right upper quadrant, epigastric region, or both; and visual disturbances

Possibly papilledema, visual field deficits, and lung crackles (in addition to edema), detected during physical examination

BP measurement

Urine protein measurement

CBC, electrolytes, BUN, glucose, creatinine, liver function tests


Tender unilateral swelling in a leg or calf, erythema (asymmetric), warmth, and sometimes fever

Manifestations often more circumscribed than in DVT

Ultrasonography to rule out DVT unless swelling is clearly localized

Examination for source of infection

DVT = deep venous thrombosis.


Evaluation aims to exclude DVT and preeclampsia. Physiologic edema is a diagnosis of exclusion.


History of present illness should include symptom onset and duration, exacerbating and relieving factors (physiologic edema is reduced by lying in the left lateral decubitus position), and risk factors for DVT and preeclampsia.

Risk factors for DVT include

  • Venous insufficiency

  • Trauma

  • Hypercoagulability disorder

  • Thrombotic disorders

  • Cigarette smoking

  • Immobility

  • Cancer

Risk factors for preeclampsia include

Review of symptoms should seek symptoms of possible causes, including the following:

  • Nausea and vomiting, abdominal pain, and jaundice: Preeclampsia

  • Pain, redness, or warmth in an extremity: DVT or cellulitis

  • Dyspnea: Pulmonary edema or preeclampsia

  • Sudden increase in weight or edema of the hands and face: Preeclampsia

  • Headache, confusion, mental status changes, blurry vision, or seizures: Preeclampsia

Past medical history should include history of DVT, pulmonary embolism, preeclampsia, and hypertension.

Physical examination

Examination begins with review of vital signs, particularly BP.

Areas of edema are evaluated for distribution (ie, whether bilateral and symmetric or unilateral) and presence of redness, warmth, and tenderness.

General examination focuses on systems that may show findings of preeclampsia. Eye examination includes testing visual fields for deficits, and funduscopic examination should check for papilledema.

Cardiovascular examination includes auscultation of the heart and lungs for evidence of fluid overload (eg, audible S3 or S4 heart sounds, tachypnea, rales, crackles) and inspection of neck veins for jugular venous distention. The abdomen should be palpated for tenderness, especially in the epigastric or right upper quadrant region. Neurologic examination should assess mental status for confusion and seek focal neurologic deficits.

Red flags

The following findings are of particular concern:

  • BP 140/90 mm Hg

  • Unilateral leg or calf warmth, redness, or tenderness, with or without fever

  • Systemic symptoms or signs of preeclampsia, particularly mental status changes

Interpretation of findings

Although edema is common during pregnancy, considering and ruling out the most dangerous causes (preeclampsia and DVT) are important:

  • If BP is > 140/90 mm Hg, preeclampsia should be considered.

  • If edema involves only one leg, particularly when redness, warmth, and tenderness are present, DVT and cellulitis should be considered.

  • Bilateral leg edema suggests a physiologic process or preeclampsia as the cause.

Clinical findings help suggest a cause (see table Some Causes of Edema During Late Pregnancy). Additional findings may suggest preeclampsia (see table Some Findings That Suggest Preeclampsia).


Some Findings That Suggest Preeclampsia

System or Body Part


Clinical Finding


Blurry vision

Visual field deficits, papilledema



Increased S3 or audible S4 heart sound

Tachypnea, rales, crackles


Nausea, vomiting, jaundice

Epigastric or right upper quadrant tenderness


Decreased urine output



Confusion, headache

Abnormal mental status


Weight gain that is sudden and dramatic

Edema of legs, face, and hands



Petechiae, purpura


If preeclampsia is suspected, urine protein is measured; hypertension plus proteinuria indicates preeclampsia. Urine dipstick testing is used routinely, but if diagnosis is unclear, urine protein may be measured in a 24-h collection. Many laboratories can more rapidly assess urine protein by measuring and calculating the urine protein:urine creatinine ratio.

If DVT is suspected, lower-extremity duplex ultrasonography is done.


Specific causes are treated.

Physiologic edema can be reduced by the following:

  • Intermittently lying on the left side (which moves the uterus off the inferior vena cava)

  • Intermittently elevating the lower extremities

  • Wearing elastic compression stockings

  • Wearing loose clothing that does not restrict blood flow, particularly in the legs

Key Points

  • Edema is common and usually benign (physiologic) during late pregnancy.

  • Physiologic edema is reduced by lying in the left lateral decubitus position, elevating the lower extremities, using compression stockings, and wearing loose clothing that does not restrict blood flow.

  • Hypertension and proteinuria indicate preeclampsia.

  • Unilateral leg edema, redness, warmth, and tenderness require evaluation for DVT.

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