What is the recommended treatment for asthma during pregnancy?

Treatment of Asthma During Pregnancy

Pregnant women with asthma should continue their asthma medications, as it is safer to treat asthma during pregnancy than to have uncontrolled symptoms and exacerbations that can cause maternal hypoxia and adverse fetal outcomes. 1, 2

Core Treatment Principle

Uncontrolled asthma poses greater risks to both mother and fetus than the potential risks of asthma medications 2, 3. Poorly controlled asthma increases the risk of:

• Perinatal mortality 2
• Preeclampsia 2, 4
• Preterm delivery 2, 4
• Low birth weight infants 2, 4
• Maternal morbidity and mortality 4

Stepwise Pharmacologic Treatment Algorithm

Step 1: Mild Intermittent Asthma

• Albuterol is the preferred short-acting beta-agonist (SABA) for as-needed symptom relief (2-4 inhalations as needed) due to its established safety profile during pregnancy 2
• For acute exacerbations: up to 3 treatments at 20-minute intervals or single nebulizer treatment 2

Step 2: Mild Persistent Asthma

• Daily low-dose inhaled corticosteroid (ICS) is the preferred treatment 1, 2
• Budesonide is the preferred ICS because it has the most safety data in pregnant women, is FDA Pregnancy Category B, and has not been associated with increased risk of major malformations, intrauterine growth restriction, preterm delivery, or low birth weight at usual doses 3, 5
• Large birth registry data are reassuring for ICS use during pregnancy 1

Step 3: Moderate Persistent Asthma

Two preferred treatment options exist 1:

1. Low-dose ICS + long-acting beta-agonist (LABA) combination 1, 2, 3

   • Salmeterol has historically been preferred due to longer U.S. experience 1
   • Formoterol is acceptable if the patient was well-controlled on it before pregnancy 3
   • Evidence from non-pregnant adults shows adding LABA to low-dose ICS provides better control than increasing ICS dose alone 1

2. Increase ICS to medium-dose range (preferably budesonide) 1, 2

Step 4: Severe Persistent Asthma

• Increase ICS to high-dose range, with budesonide preferred 1, 2
• If insufficient control persists, add systemic corticosteroids 1
• While data on oral corticosteroid risks are uncertain, severe uncontrolled asthma poses definite risks to mother and fetus 1

Management of Acute Exacerbations

Asthma exacerbations must be managed aggressively during pregnancy because they can lead to severe fetal problems through maternal hypoxia 1, 2. Treatment includes:

• Short-acting beta-agonists (albuterol preferred) 2
• Systemic corticosteroids when indicated 1, 2
• Goal: achieve peak expiratory flow rate or FEV1 ≥70% predicted 4

Monitoring During Pregnancy

• Monthly assessments of asthma history and pulmonary function are recommended, as asthma improves in one-third of women and worsens in one-third during pregnancy 2
• Serial ultrasounds starting at 32 weeks gestation should be considered for patients with suboptimally controlled asthma or moderate-to-severe disease 2
• Peak expiratory flow rate and/or spirometry (FEV1) monitoring for those with persistent asthma 4

Management of Comorbid Conditions

Rhinitis, sinusitis, and gastroesophageal reflux frequently worsen during pregnancy and can exacerbate asthma 1. Treatment includes:

• Intranasal corticosteroids are the most effective for allergic rhinitis with low systemic effects at recommended doses 1
• Loratadine or cetirizine are the preferred second-generation antihistamines 1
• Montelukast can be used for allergic rhinitis but has minimal pregnancy data 1
• Avoid oral decongestants in early pregnancy due to potential association with rare birth defects 1

Alternative Medications (Not Preferred)

• Leukotriene receptor antagonists: Can be continued if asthma was well-controlled before pregnancy, but are not preferred for initiation 1
• Theophylline: Has demonstrated effectiveness but requires careful dose titration and monitoring (target serum level 5-12 mcg/mL) due to potential for serious toxicity and drug interactions 1
• Cromolyn: Excellent safety profile but limited effectiveness compared to ICS 1

Critical Pitfalls to Avoid

• Never discontinue asthma medications during pregnancy due to unfounded safety concerns—this leads to poor asthma control and increases risks to mother and fetus 2, 3
• Never undertreate acute exacerbations—maternal hypoxia causes adverse fetal outcomes 2, 3
• Do not unnecessarily switch medications (e.g., from formoterol to salmeterol) if the patient was previously well-controlled 3
• Avoid active and passive smoking—the most modifiable risk factor for asthma complications 6

Labor and Delivery Considerations

• Continue asthma medications throughout labor and delivery 4
• Beta-agonists may interfere with uterine contractility, so use during labor should be restricted to patients where benefits clearly outweigh risks 7
• Encourage breastfeeding postpartum 4