ICS Not Linked to Birth Defect Risk in Early Pregnancy, With Anick Bérard, PhD

First-trimester exposure to inhaled corticosteroid (ICS) monotherapy, montelukast, and combination therapies with long-acting beta agonists (LABA) did not show an increased risk of major congenital malformations compared with no asthma medication use, according to new population-based data.

In an interview with HCPLive, Anick Bérard, PhD, from CHU Sainte-Justine, described these results as “reassuring.” She mentioned how many women with unexpected pregnancies may not find out that they are pregnant until 6 or 7 weeks later. However, this data shows that taking asthma medication during pregnancy is safe.

“The GINA guidelines say asthmatic women should be treated in pregnancy, and our study [with] a large cohort [is]… confirming what the guidelines are saying,” Bérard said. She noted that smaller datasets originally informed these guidelines, standing for Global Initiative for Asthma, whereas the current study provides confirmation using a substantially larger cohort.

Bérard and colleagues’ analysis included a large cohort of > 44,000 singleton births among women with asthma and compared multiple commonly used controller therapies during the first trimester. Regimens included montelukast, inhaled corticosteroids (ICS), ICS plus long-acting beta agonists (LABA), and montelukast plus ICS plus LABA combination.

She also cautioned that the study does not address all pregnancy outcomes, such as preterm birth or low birth weight, which require further investigation. Additionally, she noted that the cohort largely included women with private insurance, indicating a higher socioeconomic profile that may limit generalizability.

Overall, the data support ongoing use of ICS monotherapy and ICS/LABA combinations when clinically indicated.

“It's reassuring for prescribers, but also for pregnant women themselves, because we're all worried about major congenital malformation,” Bérard said. “The quality of life and health of the mother is as important as the health of the fetus, although in pregnancy, we prescribe for a maternal condition, but we don't always worry about the health of the mom. We worry about the health of the unborn child. Results like ours will put women at ease that they can, and they should be treated. It will have a beneficial impact on themselves, but it will not have an impact on their fetus, at least during the first trimester.”

Watch part 1 of our interview with Bérard here: Asthma Controllers Safe in First Trimester, With Anick Bérard, PhD.

References

Jiao XF, Leal LF, Ducharme FM, Tse SM, Bérard A. First-trimester asthma controller medication use and major congenital malformation risk in offspring of women with asthma: A nationwide population-based cohort study. J Allergy Clin Immunol. Published online March 31, 2026. doi:10.1016/j.jaci.2026.03.013