Is it safe to continue inhaled corticosteroids (e.g., budesonide) and long‑acting β2‑agonists during pregnancy?

Safety of Inhaled Corticosteroids and LABAs During Pregnancy

Yes, it is safe and strongly recommended to continue inhaled corticosteroids (particularly budesonide) and long-acting β2-agonists during pregnancy, as the risks of uncontrolled asthma far exceed any theoretical medication risks. 1

Primary Recommendation: Continue Asthma Medications

Inhaled corticosteroids and LABAs should be continued throughout pregnancy because poorly controlled asthma poses substantially greater risks to both mother and fetus than the medications themselves. 1, 2, 3

• Uncontrolled asthma increases risks of preeclampsia, preterm delivery, low birth weight, intrauterine growth restriction, and perinatal mortality 1, 4, 3
• Maternal hypoxia from asthma exacerbations has well-documented adverse fetal effects, while inhaled medications have been used for many years without documentation of fetal harm 1
• It is safer for pregnant women with asthma to be treated with asthma medications than to have asthma symptoms and exacerbations 4, 5

Inhaled Corticosteroid Selection

Budesonide is the preferred inhaled corticosteroid during pregnancy due to the most extensive safety data. 1, 6, 7

• Budesonide has FDA Pregnancy Category B classification and Australian TGA Category A classification 1, 6
• Large Swedish registry data from 2,534 infants exposed to inhaled budesonide in early pregnancy showed congenital malformation rates of 3.6% versus 3.5% in the general population—no increased risk 7
• At usual doses, budesonide has not been associated with increased risk of major malformations, intrauterine growth restriction, preterm delivery, or low birth weight 1

However, if a woman was well-controlled on a different inhaled corticosteroid before pregnancy (fluticasone, beclomethasone, etc.), continue that medication rather than switching. 1, 6

• Switching medications risks destabilizing asthma control, which poses greater danger than continuing a non-budesonide ICS 1
• One caveat: doses >1,000 mcg/day of beclomethasone may carry a small increased risk of congenital malformations, so use the lowest effective dose 1

Long-Acting β2-Agonist Selection

LABAs are safe to continue during pregnancy when needed for asthma control. 1, 8

• Salmeterol has more pregnancy experience and is historically preferred 1
• Formoterol has limited human data but reassuring animal data suggesting low risk, and if a woman was well-controlled on formoterol pre-pregnancy, it is acceptable to continue the same medication 1, 8
• The pharmacologic profile of formoterol is similar to short-acting β2-agonists like albuterol, which have extensive reassuring pregnancy data from over 6,600 pregnant women 9, 8

Short-Acting β2-Agonists for Rescue

Albuterol (salbutamol) is the preferred short-acting bronchodilator during pregnancy. 1, 9

• Safety data from 6,667 pregnant women (including 1,929 with asthma) show no increased risk of structural anomalies compared to the general population 9
• Dosing: 2-4 puffs via metered-dose inhaler as needed for symptoms 1, 9
• If albuterol is needed more than twice weekly, this signals inadequate asthma control requiring initiation or intensification of inhaled corticosteroid therapy 1, 9

Monitoring Requirements

Monthly evaluation of asthma control and pulmonary function is essential throughout pregnancy. 9, 4, 10

• Asthma course improves in one-third of women and worsens in one-third during pregnancy, justifying regular follow-up 9
• Objective monitoring should include peak expiratory flow rate, spirometry (FEV1), or both 4
• Pregnancies complicated by moderate or severe asthma may benefit from serial fetal ultrasound examinations starting at 32 weeks gestation 9, 4

Management of Acute Exacerbations

Asthma exacerbations during pregnancy must be aggressively managed with systemic corticosteroids and bronchodilators. 4, 3, 10

• For acute exacerbations: nebulized albuterol 2.5 mg every 20 minutes for 3 doses, then every 1-4 hours as needed 9
• For severe exacerbations: combine ipratropium 0.5 mg + albuterol 2.5 mg every 20 minutes for 3 doses 9
• Systemic corticosteroids should be used when indicated despite small increased risks (oral clefts, preeclampsia), as these risks are less than the potential risks of severe uncontrolled asthma 1, 5

Common Pitfalls to Avoid

Do not discontinue or de-escalate asthma medications during pregnancy due to unfounded safety concerns. 8, 3

• This is the most common error and leads to poor asthma control with increased maternal and fetal risks 3, 10
• Evidence suggests that both chronic asthma and acute exacerbations remain undertreated in pregnancy 3

Do not switch from formoterol to salmeterol unnecessarily if the patient was previously well-controlled on formoterol. 1, 8

Do not fail to aggressively manage asthma exacerbations during pregnancy. 1, 3

• Maternal hypoxia poses immediate fetal risk and requires prompt treatment 1

Breastfeeding Considerations

All inhaled corticosteroids and LABAs are compatible with breastfeeding. 1, 6

• Minimal systemic absorption and negligible transfer into breast milk 1, 6
• Asthma medications should be continued during lactation 4