Is it safe to continue inhaled corticosteroids during the first trimester of pregnancy?

Asthma affects about 3%–12% of pregnant women worldwide. Control of asthma during pregnancy is critical to prevent maternal and perinatal complications. Asthma guidelines recommend continuing inhaled corticosteroids (ICSs) during pregnancy, with emphasis on use of ICSs as a mainstay of management because of their favourable safety profile and lower systemic absorption compared with oral medications. However, discontinuation of ICSs in early pregnancy is common, possibly due to concerns about potential fetal harm, medication-related anxiety, or conservative prescribing practices. Clinical evidence of major maternal and neonatal outcomes after first trimester ICS use for women with asthma remains limited.To examine this issue, researchers evaluated the association between ICS continuation during the first trimester of pregnancy and maternal and neonatal outcomes. A nationwide, population-based cohort study was conducted using a mother-child linked healthcare database that included live births in Korea from April 2010 to the end of 2022. Women (aged 15–50 years) with asthma who received at least two prescriptions for ICSs in the six months before their last menstrual period were identified to increase the likelihood that prescription records reflected ongoing ICS use. The researchers focused on the first trimester as this period represents a clinically critical window during which women often become aware of pregnancy and may discontinue or modify medication use. Women were classified as ICS continuers (at least one ICS prescription during the first trimester) or discontinuers (no ICS prescription during the same period). Maternal outcomes included preeclampsia, gestational diabetes, obstructed labour, antepartum hemorrhage, premature rupture of membranes and preterm birth. Neonatal outcomes included hypoxia or asphyxia, low birth weight and congenital malformations. Propensity score regression models were used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) for each maternal and neonatal outcome.Key results:Among 3,909,084 pregnancies, 6,105 involved prepregnancy ICS use for asthma.A total of 2,108 women (34.5%; mean age 33.2 years) continued ICS in the first trimester, and 3,997 women (65.5%; mean age 32.9 years) discontinued use.Risks per 1000 pregnancies for ICS continuation vs discontinuation, respectively, were as follows: gestational diabetes, 145.6 vs 131.9 (weighted RR, 1.05; 95% CI, 0.90–1.22)preterm birth, 131.4 vs 128.6 (weighted RR, 0.95; 95% CI, 0.82–1.11)low birth weight, 77.5 vs 58.3 (weighted RR, 1.11; 95% CI, 0.89–1.39)congenital malformations, 57.6 vs 42.2 (weighted RR, 1.22; 95% CI, 0.94–1.56). Continuation of ICSs was not associated with increased risks of these or other maternal and neonatal outcomes.This Korean nationwide cohort study found that only about one-third of women (34.5%) continued ICS treatment for asthma during the first trimester of pregnancy. Compared with discontinuation, continued ICS use during early pregnancy was not associated with increased risks of adverse maternal or neonatal outcomes. These findings provide reassuring evidence supporting current guideline recommendations to continue ICS therapy when indicated for asthma during pregnancy.Reference:Suh B, Cho Y, Choi EY, et al. Inhaled corticosteroids continuation in the first trimester and pregnancy outcomes in women with asthma. JAMA Network Open 2026;9(8):e2630781. (accessed August 25, 2026).

Is it safe to continue inhaled corticosteroids during the first trimester of pregnancy?

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