Management of Asthma During Pregnancy
Asthma medications should be continued and even escalated during pregnancy, as uncontrolled asthma poses far greater risks to both mother and fetus than the medications themselves. 1, 2
Core Management Principles
Aggressive treatment is mandatory because inadequate asthma control increases risks of perinatal mortality, pre-eclampsia, preterm birth, low birth weight, and growth restriction 2, 3. Maintaining maternal lung function is essential to ensure adequate fetal oxygenation 2.
Monthly Monitoring Throughout Pregnancy
- Conduct monthly evaluations of asthma symptoms and pulmonary function (peak expiratory flow or spirometry measuring FEV1) throughout the entire pregnancy 1, 2, 3
- Asthma unpredictably improves in one-third of pregnant women and worsens in one-third, necessitating regular therapy adjustments 2, 4
Long-Term Controller Therapy
Inhaled Corticosteroids (First-Line)
- Budesonide is the preferred inhaled corticosteroid due to the most extensive safety data during pregnancy and FDA Pregnancy Category B classification 1, 2, 5, 6
- Other inhaled corticosteroids (Pregnancy Category C) may be continued if asthma was well-controlled before pregnancy 6
- Inhaled corticosteroids should be used for all levels of persistent asthma using step-care approach 3, 4
Additional Controller Options
- Long-acting beta-agonists, leukotriene receptor antagonists, and long-acting muscarinic antagonists can be used when clinically indicated 7
- Biologic therapies may be continued even without definitive pregnancy safety data when benefits outweigh risks 7
Acute Exacerbation Management
Immediate Bronchodilator Therapy
- Albuterol is the preferred short-acting beta-agonist due to extensive pregnancy safety data 1, 2, 5
- Dosing: 2.5 mg via nebulizer or 4-8 puffs via MDI every 20 minutes for 3 doses, then every 1-4 hours as needed 1
- Add ipratropium bromide 0.25 mg via nebulizer or 4-8 puffs via MDI every 20 minutes for 3 doses for severe exacerbations 1
Systemic Corticosteroids
- Add oral corticosteroids when exacerbations are not quickly controlled with bronchodilators 1, 2
- Outpatient dosing: Prednisone 40-60 mg daily for 3-10 days 1, 2
- Severe exacerbations: Prednisone 120-180 mg/day in 3-4 divided doses for 48 hours, then 60-80 mg/day until peak expiratory flow reaches 70% of predicted or personal best 1, 2, 3
Hospital Management
- Obtain arterial blood gas in severe cases to assess maternal and fetal oxygenation 1
- Involve obstetrical care provider in assessment and monitoring 1
Fetal Monitoring Considerations
- Serial ultrasounds starting at 32 weeks gestation should be performed for patients with moderate to severe asthma or suboptimally controlled asthma 1, 3
- This allows assessment of fetal growth and well-being in higher-risk pregnancies 3
Critical Pitfalls to Avoid
- Never withhold or reduce asthma medications due to pregnancy concerns—this is the most dangerous error, as uncontrolled asthma causes greater harm than medication exposure 1, 2, 5
- Avoid oral decongestants in early pregnancy due to potential associations with cardiac, ear, gut, and limb abnormalities 1, 5
- Do not undertreat exacerbations; aggressive management is essential 1, 4
Post-Exacerbation Management
- Step down therapy to the least medication necessary to maintain control after resolving the exacerbation 1, 2
- Review medication technique, adherence, and environmental triggers 2
- Consider stepping up long-term controller therapy if exacerbations are frequent 2