What are the recommendations for shortness of breath (dyspnea) in pregnancy?

Management of Shortness of Breath in Pregnancy

Shortness of breath (dyspnea) in pregnancy requires careful evaluation to distinguish between physiologic changes and pathologic conditions, as failure to identify serious underlying causes can lead to significant maternal and fetal morbidity and mortality.

Physiologic vs. Pathologic Dyspnea

Physiologic Dyspnea

• Occurs in approximately 50% of pregnant women during exertion and 20% at rest 1
• Typically gradual onset, non-progressive, and not associated with hypoxemia
• Usually worsens in the third trimester due to diaphragmatic elevation
• Not associated with significant functional limitation

Pathologic Warning Signs

• Progressive worsening of symptoms
• Dyspnea at rest
• Associated hypoxemia (oxygen saturation <95%)
• Orthopnea or paroxysmal nocturnal dyspnea
• Chest pain, palpitations, or syncope
• Significant functional limitation

Diagnostic Approach

Initial Assessment

1. Oxygen saturation measurement - immediate assessment for hypoxemia
2. Vital signs - tachycardia, tachypnea, fever, hypertension
3. Cardiac and pulmonary examination - murmurs, rales, wheezes, decreased breath sounds
4. Lower extremity examination - edema, signs of DVT

First-line Investigations

• ECG - to assess for arrhythmias or ischemic changes
• Echocardiography - for unexplained or new cardiovascular signs/symptoms 2
• Chest X-ray (with fetal shielding) - if other methods fail to clarify the cause of dyspnea 2

Additional Testing Based on Clinical Suspicion

• D-dimer and modified Wells score - for suspected pulmonary embolism 3
• Bilateral compression ultrasound - if DVT symptoms are present 3
• CTPA or V/Q scan - for suspected PE based on clinical presentation 3
• Pulmonary function tests - for suspected respiratory disorders

Common Pathologic Causes

Pulmonary Embolism

• Leading cause of maternal death in high-income countries 3
• Risk increases during pregnancy, peaks postpartum
• Cesarean section increases risk 20-fold compared to vaginal delivery 3
• Management: Immediate anticoagulation with LMWH while diagnostic workup is ongoing 3

Cardiac Disease

• Shortness of breath may be the first manifestation of underlying heart disease
• Women with NYHA class I or II heart disease can usually exercise below their threshold of symptoms 2
• Women with NYHA class III or IV are at high risk during pregnancy 2
• Management: Refer to specialized centers with multidisciplinary teams 2

Respiratory Disorders

• Asthma exacerbations
• Pneumonia
• Pneumothorax (rare but serious) 4
• Management: Continue usual asthma medications during pregnancy and labor 2, 5

Peripartum Cardiomyopathy

• Can present in the last month of pregnancy or within 5 months postpartum 6
• Characterized by left ventricular systolic dysfunction (EF <45%)
• Management: Standard heart failure therapy modified for pregnancy safety

Management Recommendations

Mild-Moderate Respiratory Disease

• Continue regular use of bronchodilators and inhaled corticosteroids 2
• Remain physically active below threshold of exercise intolerance 2
• Albuterol is pregnancy category C but can be used when benefits outweigh risks 5

Severe Respiratory Disease

• Severe respiratory disorders (GOLD 3-4 COPD, FEV <60% asthma, severe restrictive lung disease) should avoid moderate-to-vigorous physical activity 2
• Maintain activities of daily living below threshold of intolerance 2
• Monitor oxygen saturation closely

Cardiac Disease

• Women with heart disease should be referred to specialized centers with multidisciplinary teams 2
• Echocardiography for any pregnant patient with unexplained cardiovascular symptoms 2
• Consider MRI (without gadolinium) if echocardiography is insufficient 2

Pulmonary Embolism

• Institute anticoagulation therapy as soon as possible while diagnostic workup is ongoing 3
• LMWH is the preferred agent in pregnancy 3
• Thrombolysis should not be used peripartum except in life-threatening PE 3

Special Considerations

Delivery Planning

• Women with severe respiratory or cardiac disease require multidisciplinary planning for delivery
• Consider epidural analgesia for women with severe respiratory disease 2
• Caesarean delivery should be considered for obstetric indications or severe cardiac/respiratory compromise 2

Postpartum Vigilance

• Postpartum period is a vulnerable time with risks of cardio-respiratory decompensation 2
• Maintain close monitoring for women with underlying cardiac or respiratory disease
• Be alert for new-onset dyspnea postpartum, which may indicate peripartum cardiomyopathy or pulmonary embolism 6

Common Pitfalls

• Dismissing dyspnea as normal in pregnancy without appropriate evaluation
• Failing to consider pulmonary embolism in pregnant women with dyspnea
• Inadequate monitoring of women with known cardiac or respiratory disease
• Delaying imaging studies due to radiation concerns (fetal radiation exposure from CTPA is minimal at 0.003-0.02 mSv) 3
• Not recognizing that shortness of breath may be the first manifestation of previously undiagnosed cardiac disease 2