From the Guidelines
The workup for shortness of breath in pregnancy should begin with a thorough history and physical examination to distinguish between physiologic dyspnea of pregnancy and pathologic causes. Initial assessment should include vital signs (including oxygen saturation), respiratory rate, and evaluation for signs of respiratory distress. Laboratory tests should include complete blood count to assess for anemia, comprehensive metabolic panel, and D-dimer (though this is often elevated in normal pregnancy) 1.
Key Considerations
- Chest X-ray with abdominal shielding is safe and should be performed when clinically indicated 1.
- Pulmonary function tests can help distinguish between obstructive and restrictive lung diseases.
- Electrocardiogram and echocardiogram may be necessary if cardiac causes are suspected.
- Arterial blood gases can assess oxygenation status in severe cases.
Pathologic Causes
- Common pathologic causes to consider include pulmonary embolism (requiring CT pulmonary angiography or V/Q scan), asthma exacerbation, pneumonia, peripartum cardiomyopathy, and pulmonary edema.
- It's essential to remember that physiologic dyspnea of pregnancy is common due to increased oxygen demand, elevated diaphragm, and respiratory alkalosis, but should never be accompanied by hypoxemia or severe symptoms 1.
Clinical Approach
- The workup should be tailored to the clinical presentation, with more urgent and comprehensive evaluation for severe symptoms, abnormal vital signs, or concerning physical exam findings.
- In cases of suspected pulmonary embolism, a normal D-dimer value has the same exclusion value for PE in pregnant women as in other patients with suspected PE, and should be measured to avoid unnecessary exposure of the fetus to X-rays 1.
- For patients with an abnormal D-dimer level, leg vein imaging should be performed by compression US, and if negative, further diagnostic tests such as CT pulmonary angiography or V/Q scan may be necessary 1.
From the Research
Workup for Shortness of Breath in Pregnancy
The workup for shortness of breath (dyspnea) in pregnancy involves a comprehensive evaluation to determine the underlying cause. Some possible causes of dyspnea in pregnancy include:
- Cardiac factors, such as pulmonary hypertension or peripartum cardiomyopathy 2, 3, 4
- Respiratory issues, such as asthma or pneumonia
- Anemia or other hematological disorders
- Thyroid disorders
Diagnostic Tests
The following diagnostic tests may be ordered as part of the workup for dyspnea in pregnancy:
- Chest X-ray or computed tomography (CT) scan to evaluate the lungs and heart 5
- Echocardiogram to assess cardiac function and rule out pulmonary hypertension or other cardiac abnormalities 3
- Complete blood count (CBC) to evaluate for anemia or other hematological disorders
- Thyroid function tests to rule out thyroid disorders
- Pulmonary function tests (PFTs) to evaluate lung function
Special Considerations in Pregnancy
When evaluating dyspnea in pregnancy, it is essential to consider the unique physiological changes that occur during pregnancy. For example:
- Pregnancy can induce or unmask myocardial dysfunction, leading to dyspnea 3
- The increased blood volume and cardiac output during pregnancy can lead to increased pulmonary artery pressure 3
- The risk of thromboembolism is increased during pregnancy, and dyspnea can be a symptom of a pulmonary embolism
Management
The management of dyspnea in pregnancy depends on the underlying cause. Some possible treatments include: