ASTHMA exacerbations during pregnancy remain a significant risk for both maternal and perinatal outcomes, with reduced inhaled corticosteroid (ICS) use identified as a key modifiable factor, according to a UK cohort study.
Researchers analysed data from 40,196 pregnant women with asthma using linked primary care and hospital records spanning 2004–2020. Exacerbations were defined as short courses of oral corticosteroids, emergency department visits, or unscheduled hospital admissions. Multivariable logistic regression assessed associations between maternal characteristics, ICS use, and exacerbation risk, focusing on modifiable factors.
Overall, total asthma exacerbations declined by approximately 30% during pregnancy. However, hospital-associated exacerbations increased by 30–45% during the second and third trimesters, dropping sharply after delivery. One-third of women reduced ICS prescriptions during pregnancy, and this reduction was strongly linked to increased exacerbation risk (adjusted odds ratio [aOR]: 2.29, 95% CI: 2.12–2.47). Pre-pregnancy asthma control also influenced outcomes: a history of exacerbations carried the highest risk (aOR: 4.09, 95% CI: 3.81–4.39), while women with ≥4 ICS-plus-another-preventer prescriptions per year before pregnancy had elevated risk (aOR: 2.11, 95% CI: 1.87–2.37). Other risk factors included blood eosinophilia, smoking, obesity, age, and ethnicity. Notably, ICS reduction was often avoidable, yet it represented the second largest driver of hospitalisation risk.
The study highlights a critical window for intervention: maintaining ICS adherence and optimising asthma control before and during pregnancy could substantially reduce severe exacerbations requiring hospital care. Clinicians should prioritise patient education, close monitoring, and personalised treatment plans for high-risk women.
Reference
Lee B et al. Pregnancy, asthma and exacerbations: a population-based cohort. Eur Respir J. 2025; DOI:10.1183/13993003.01327-2025.
