Inhaled Steroids Safe in First Trimester
A South Korean cohort study found no increased risk of major maternal or neonatal outcomes for women who continued inhaled corticosteroids (ICS) during early pregnancy.
Women who kept using inhaled corticosteroids in the first trimester of pregnancy did not experience higher rates of adverse maternal or neonatal outcomes compared with those who stopped, according to a nationwide cohort study from South Korea.
The research, published in JAMA Network Open, examined data from 3,909,084 pregnancies between 2010 and 2022. Of the 6,105 pregnancies that met the study criteria-women aged 15 to 50 with an asthma diagnosis and at least two prescriptions for an inhaled corticosteroid in the six months before conception-only 34.5 % (2,108 women, mean age 33.2) continued their inhaled therapy during the first trimester. The remaining 65.5 % (3,997 women, mean age 32.9) discontinued use.
The investigators compared a range of outcomes, including gestational diabetes, preeclampsia, preterm birth, low birth weight, and congenital malformations. The risks per 1,000 pregnancies for those who continued versus those who discontinued were:
| Outcome | Continued | Discontinued | Weighted RR (95 % CI) |
|---|---|---|---|
| Gestational diabetes | 145.6 | 131.9 | 1.05 (0.90-1.22) |
| Preeclampsia | 21.8 | 13.3 | 1.14 (0.74-1.75) |
| Preterm birth | 131.4 | 128.6 | 0.95 (0.82-1.11) |
| Low birth weight | 77.5 | 58.3 | 1.11 (0.89-1.39) |
| Congenital malformations | 57.6 | 42.2 | 1.22 (0.94-1.56) |
No statistically significant differences emerged after adjusting for confounding factors. The authors noted that the similarity in outcomes should be viewed in light of potential baseline severity differences, and that asthma management should remain individualized.
The study also described medication patterns among the two groups. Women who continued inhaled corticosteroids were more likely to be first-time mothers (50.0 % vs 37.6 %) and used fewer antibiotics (86.2 % vs 92.7 %), NSAIDs (68.3 % vs 78.1 %), acetaminophen (67.0 % vs 74.3 %), and dihydrocodeine (59.5 % vs 72.5 %). They were more likely to receive high-dose oral corticosteroids (≥180 mg) (17.5 % vs 8.4 %) but less likely to receive low-dose oral corticosteroids (≥50 mg) (7.4 % vs 13.0 %). These patterns suggest that women with more severe asthma were more inclined to continue inhaled therapy.
The authors highlighted that inadequate asthma control may raise maternal and neonatal risks, underscoring the importance of maintaining optimal disease management throughout pregnancy. They also acknowledged limitations, including the possibility that prescription records do not reflect actual medication use, potential misclassification, unmeasured confounders, and selection bias from only including live births. The study design does not establish causality.
Asthma affects 3 % to 12 % of pregnant women worldwide, and 20 % experience exacerbations. When poorly controlled, asthma can harm both mother and child. Current guidelines recommend continuing inhaled corticosteroids during pregnancy, yet many women stop early. This Korean study provides reassuring evidence that continuing inhaled corticosteroids in the first trimester does not increase major adverse outcomes.
For clinicians and patients seeking data on medication safety, the study’s findings align with other cohort research and support the continued use of inhaled corticosteroids in early pregnancy. The detailed data sets used in the analysis are comparable to the large-scale health records referenced in our stats page, offering a useful benchmark for future research.
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The study’s authors, led by Yunha Noh, PharmD, PhD of Chonnam National University in Gwangju, emphasize that individual assessment remains key. Women should discuss their asthma treatment plans with their healthcare providers to balance disease control with pregnancy safety.
The research adds to a growing body of evidence that inhaled corticosteroids are safe for use during the first trimester, providing clinicians and patients with data to inform shared decision-making.
