Are inhalers (inhalation devices) safe to use during pregnancy?

Inhaler Safety During Pregnancy

Most inhaled medications used for respiratory conditions are safe during pregnancy, with the benefits of controlling respiratory diseases outweighing potential risks to the fetus. 1

Safety of Specific Inhaler Types

Short-Acting Beta-Agonists (SABAs)

• Salbutamol (albuterol): Classified as compatible for use during pregnancy 1
  • Preferred SABA during pregnancy due to extensive experience and excellent safety profile 1
  • No evidence of fetal injury from use during pregnancy 1
  • Safe during breastfeeding 1

Long-Acting Beta-Agonists (LABAs)

• Salmeterol: Classified as "probably safe" during pregnancy 1
  • Preferred LABA due to greater experience during pregnancy 1
• Formoterol: Also classified as "probably safe" 1
  • Limited human data, but animal studies suggest low risk 1
  • Can be continued if woman was well-controlled on it before pregnancy 1

Ultra-Long-Acting Beta-Agonists (Ultra-LABAs)

• Olodaterol and Vilanterol: Classified as "possibly safe" 1
  • Limited human data available 1

Long-Acting Muscarinic Antagonists (LAMAs)

• Tiotropium bromide: Classified as "possibly safe" 1
  • Minimal experience during human pregnancy 1
  • Animal studies show no teratogenic effects 1
  • Compatible with breastfeeding 1

Inhaled Corticosteroids (ICSs)

• Budesonide: Preferred inhaled corticosteroid during pregnancy 1
  • Most data available on its use during pregnancy 1
  • No increased risk of congenital malformations observed in studies of over 6,600 infants 2
  • FDA Pregnancy Category B (other ICSs are Category C) 2
• Other ICSs (beclomethasone, fluticasone, etc.):
  • No evidence indicating they are unsafe during pregnancy 1
  • Can be continued if woman was well-controlled on them before pregnancy 1
  • Meta-analysis shows ICSs do not increase risk of major malformations, preterm delivery, low birth weight, or pregnancy-induced hypertension 3

Risk-Benefit Assessment

Benefits of Inhaler Use During Pregnancy

• Prevents asthma exacerbations which can cause maternal hypoxia and adverse fetal effects 1
• Maintains maternal lung function and blood oxygenation, ensuring oxygen supply to fetus 1
• Reduces risk of pregnancy complications associated with poorly controlled respiratory disease 4

Risks of Untreated Respiratory Disease

• Increased perinatal mortality 4
• Higher risk of preeclampsia 4
• Increased risk of preterm birth 4
• Higher likelihood of low birth weight babies 4

Clinical Recommendations

1. Continue inhaler therapy throughout pregnancy if needed for respiratory disease control 1
2. Prefer medications with more safety data:
   • Albuterol (salbutamol) for rescue therapy 1
   • Budesonide as first-choice inhaled corticosteroid 1
3. Maintain pre-pregnancy controller medications if they were effective, especially if changing might jeopardize disease control 1
4. Monitor respiratory function regularly during pregnancy:
   • Monthly evaluations recommended 4
   • Spirometry preferred for initial assessment 4
   • Peak flow monitoring sufficient for follow-up visits 4

Common Pitfalls to Avoid

1. Undertreating respiratory disease due to unfounded concerns about medication safety 4
2. Failing to recognize that uncontrolled respiratory disease poses greater risks to mother and fetus than medication side effects 4
3. Improper inhaler technique, which is common in pregnant women (64.4% in one study) and may reduce medication effectiveness 5
4. Discontinuing controller medications during the first trimester due to concerns about teratogenicity 6

Special Considerations

• For women with asthma, inhaled medications have been used for many years without documentation of adverse effects on the fetus 1
• ICSs should be used at the lowest effective dose to control symptoms, though doses up to 1000 μg/day (beclomethasone equivalent) are generally considered safe 6
• Patient education on proper inhaler technique is essential, as errors are common during pregnancy 5

In summary, the use of inhalers during pregnancy should be guided by the principle that the risks of uncontrolled respiratory disease far outweigh the potential risks of inhaled medications when used appropriately.