How to Treat Asthma in Pregnancy

Written by Amanda Mathews

Spoon Feed
Most asthma therapies for daily control and acute exacerbations are safe to use in pregnancy. Keeping asthma under control while pregnant reduces maternal and fetal risks.

Treating asthma in pregnancy helps two patients
Asthma is the most common respiratory pathology affecting pregnant women with between 3-12% of patients affected. This narrative review clarifies risk associated with poorly controlled asthma to both mother and fetus, as well as acceptable controller strategies. Here are the key takeaways:

• Maternal risks of asthma include: preterm birth, low birth weight, gestational diabetes, pre-eclampsia, and cesarean delivery. Poorly controlled asthma further increases the risk for gestational diabetes and cesarean delivery. There is no increased risk of miscarriage.
• Fetal risks include: low birth weight, fetal growth restriction, preterm birth. Neonatal adverse events include NICU admission, transient tachypnea of the newborn, hypoglycemia, and neonatal seizure.
• Despite changes in cardiovascular and pulmonary physiology, a pregnant patient’s FEV1/FVC ratio should not decrease over pregnancy; any decrease should be investigated.
• Many of the most common asthma controller therapies do not pose increased teratogenic risk, including inhaled corticosteroids, short- and long-acting beta agonists, montelukast, and ipratropium. Data on biologic therapies is varied.
• There is a slightly higher risk for preterm labor and low birth weight with oral corticosteroids.
• Treat modifiable risk factors, such as adherence to therapy, respiratory viruses, nicotine replacement and smoking cessation counseling, reflux, obstructive sleep apnea, and obesity.

How will this change my practice?
This was a great review on best practices for asthma management in pregnancy. It reminds me that most medications I use for asthma treatment and prevention in non-pregnant patients can be used in this population as well. I plan to use more nuance when discussing oral corticosteroids with patients for treatment of acute exacerbations, as there are some risks associated with that commonly prescribed medication.

Source
Asthma and Pregnancy: A Narrative Review. Chest. 2025 Sep 26:S0012-3692(25)05382-6. doi: 10.1016/j.chest.2025.08.043. Epub ahead of print. PMID: 41015198.