Edema is common during late pregnancy. It typically involves the lower extremities but occasionally appears as swelling or puffiness in the face or hands.
Etiology
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
Deep venous thrombosis (DVT)
Cellulitis (see table Some Causes of Edema During Late Pregnancy)
DVT is more common during pregnancy because pregnancy is a hypercoagulable state, and women may be less mobile.
Preeclampsia is a type of pregnancy-induced hypertension; however, not all women with preeclampsia develop upper extremity or facial edema.
Peripartum cardiomyopathy is a rare but serious condition. It can cause other nonspecific symptoms of pregnancy, including dyspnea and fatigue.
When extensive, cellulitis, which usually causes focal erythema, may resemble general edema.
Evaluation
Evaluation of patients with lower-extremity edema during late pregnancy aims to exclude deep venous thrombosis (DVT), preeclampsia, peripartum cardiomyopathy, and other pathologic causes of edema. Physiologic edema is a diagnosis of exclusion.
History
History of present illness should include the estimated due date (and whether this is based on last menstrual period or ultrasonography), any risk factors for obstetric complications, and prior testing or complications during the current pregnancy. It 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, preeclampsia, and peripartum cardiomyopathy.
High-risk factors for preeclampsia include
Previous pregnancy with preeclampsia
Chronic hypertension
Type 1 or type 2 diabetes
Kidney disorders
Moderate-risk factors for preeclampsia include
First pregnancy
Obesity (body mass index > 30)
Family history of preeclampsia
African descent
Lower income
Age ≥ 35
In vitro fertilization
Personal history factors (eg, previous infants with low birth weight or small for gestational age, previous adverse pregnancy outcome, > 10-year pregnancy interval)
Risk factors for DVT include
Venous insufficiency
Trauma
Hypercoagulability disorder
Thrombotic disorders
Cigarette smoking
Immobility
Cancer
Risk factors for peripartum cardiomyopathy include
Age > 30
History of cardiomyopathy
African descent
History of hypertension and/or hypertensive disorders of pregnancy (eg, preeclampsia)
Review of symptoms should seek symptoms of possible causes, including the following:
High blood pressure, nausea, and vomiting: Preeclampsia
Pain, redness, or warmth in an extremity: DVT or cellulitis
Dyspnea: Pulmonary edema, peripartum cardiomyopathy, or preeclampsia
Sudden increase in weight or edema of the hands and face: Preeclampsia
Headache, confusion, mental status changes, blurry vision, right upper quadrant pain, or seizures: Preeclampsia
Past medical history should include history of DVT, pulmonary embolism, cardiac disease, preeclampsia, and hypertension.
Physical examination
Examination begins with review of vital signs, particularly blood pressure.
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:
Blood pressure ≥ 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
Symptoms or signs of pulmonary edema
Interpretation of findings
Although edema is common during pregnancy, considering and ruling out the most dangerous causes (preeclampsia, peripartum cardiomyopathy, and DVT) are important:
If blood pressure 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, preeclampsia, or peripartum cardiomyopathy as the cause.
Symptoms or signs of pulmonary edema, particularly in patients who have preeclampsia (or other risk factors), suggest peripartum cardiomyopathy.
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).
Testing
If DVT is suspected, lower-extremity duplex ultrasonography is done.
If peripartum cardiomyopathy is suspected, ECG, chest X-ray, and echocardiography are done. BNP (brain [B-type] natriuretic peptide) or NT-proBNP (N-terminal pro b-type natriuretic peptide) is measured.
Treatment
Specific causes of edema during pregnancy are treated.
Physiologic edema can be reduced by the following:
Intermittently lying on the left side (left lateral decubitus position), 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.
New-onset hypertension and proteinuria indicate preeclampsia; absence of proteinuria does not exclude preeclampsia.
Evaluate patients for DVT if they have unilateral leg edema, redness, warmth, and tenderness.
Evaluate patients for peripartum cardiomyopathy if they have dyspnea and if the physical examination detects evidence of fluid overload.
Because preeclampsia significantly increases the risk of peripartum cardiomyopathy, rapidly evaluate patients who have preeclampsia and possible cardiac dysfunction and/or pulmonary edema for peripartum cardiomyopathy.
