Symbicort During Pregnancy: Is It Safe?

What does the evidence say about symbicort during pregnancy?

1. Inhaled corticosteroids as a class haven't been linked to a higher overall chance of birth defects, and using an inhaled corticosteroid for asthma may lower the chance of preterm delivery compared with leaving asthma unmanaged, since poorly controlled asthma itself is tied to preterm delivery and low birth weight. 1
2. Budesonide, the inhaled corticosteroid in Symbicort, is generally preferred over other inhaled corticosteroids in pregnancy because it has the most established safety data. Major asthma guidance specifically supports standard-dose combination inhalers pairing an inhaled corticosteroid with formoterol, the long-acting bronchodilator in Symbicort, for use during pregnancy as both a daily controller and an as-needed reliever. 2
3. Animal research and observational human studies have not established a link between formoterol or salmeterol, the long-acting bronchodilators in combination inhalers like Symbicort, and worse pregnancy outcomes, though the evidence base for these combination inhalers is still less extensive than for older asthma medications. 2
4. Research on long-acting beta agonists as a category has found an increased chance of heart defects when used in the first trimester in some studies, though what's driving that signal, the medication itself versus the severity of the asthma being managed, isn't clear. This is a reason to discuss your specific asthma plan with your provider rather than stop the medication on your own. 3
5. A chick embryo study, prompted by a real clinical case of three children with a cleft lip and palate born to a woman managing bronchial asthma, found that budesonide, formoterol, and the Symbicort combination could each cause developmental abnormalities including orofacial clefts in that animal model, at doses far below what a person would inhale. This is animal, not human, data, and it hasn't been confirmed in human pregnancy studies, but it is a reason researchers are watching this question. 4

Is symbicort safe in each trimester?

• First trimester. If you're already using Symbicort for asthma, the general guidance is to keep your asthma controlled rather than stop, since poorly controlled asthma in pregnancy carries its own complications. Budesonide has the most pregnancy data of any inhaled steroid, part of why ICS-formoterol combinations are endorsed for use throughout pregnancy.
• Second trimester. Asthma symptoms can shift in either direction as pregnancy progresses, better for some people, worse for others, so this is a good point to confirm your inhaler technique and dosing still match your symptoms with your provider.
• Third trimester. Keep using your prescribed controller inhaler as directed through delivery. Well-controlled asthma going into labor lowers the chance of a flare at a time when you and your care team want your breathing steady.