Related Experiment Video
Updated: Sep 9, 2025
Noninvasive Sampling of Mucosal Lining Fluid for the Quantification of In Vivo Upper Airway Immune-mediator Levels
Published on: August 7, 2017
Pregnancy, asthma and exacerbations: a population-based cohort
Bohee Lee1, Ernie Wong1, Tricia Tan2
1National Heart and Lung Institute, Imperial College London, London, UK.
Background:
Asthma exacerbations during pregnancy are associated with adverse maternal and perinatal outcomes. Identifying modifiable risk factors is essential for improving health outcomes. We aimed to describe exacerbation patterns during pregnancy and identify exacerbation risk factors, particularly modifiable risk factors such as inhaled corticosteroid use.
Methods:
This was a cohort study using UK primary care and hospital data (2004-2020) to identify pregnant women with asthma. Exacerbations were defined as a short course of oral corticosteroids, emergency department visit or unscheduled hospital admission. Multivariable logistic regression was used to assess associations between maternal characteristics and exacerbations (primary outcome) and inhaled corticosteroid use (secondary outcome).
Results:
Among 40 196 pregnant women with asthma, total exacerbations declined by ∼30% during pregnancy. However, exacerbations associated with hospital admission increased by 30-45% during the second and third trimesters, declining abruptly after delivery. Inhaled corticosteroid prescriptions were reduced in 31% of women during pregnancy. Decreased inhaled corticosteroid use was associated with suboptimal asthma control pre-pregnancy, age, ethnicity and smoking. The strongest exacerbation risk factors were a history of exacerbations (adjusted OR 4.09, 95% CI 3.81-4.39), reduced inhaled corticosteroid use during pregnancy (adjusted OR 2.29, 95% CI 2.12-2.47) and ≥4 prescriptions per year for inhaled corticosteroids plus another preventer before pregnancy (adjusted odds ratio 2.11, 95% CI 1.87-2.37). Additional risk factors included blood eosinophilia, smoking and obesity.
Conclusions:
Despite fewer total exacerbations, exacerbations associated with a hospital admission increased during pregnancy. One third of women reduced inhaled corticosteroid use during pregnancy, yet this was the second largest exacerbation risk factor and is completely modifiable. Other major risk factors were type 2 inflammation and another modifiable risk factor, suboptimal asthma control pre-pregnancy.
Related Concept Videos
01:29Asthma-I: Introduction
01:24Asthma-III: Symptoms and Complications
Classification of Asthma
01:30Asthma-IV: Diagnostic and Management
Clinical Assessment for Asthma:
This is the first step in diagnosing and managing asthma. It includes:
01:23Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by...
01:20Asthma: Pathogenesis and Management
Asthma is classified as allergic and non-allergic. Allergens such as dust mites, pollen, and pet dander trigger allergic asthma, while factors like cold air, intense emotions, or exercise can induce non-allergic asthma.
01:26Asthma-II: Pathophysiology and Classification
Additionally, environmental and genetic factors play crucial roles in determining an individual's susceptibility to asthma and the severity of their condition.
Critical processes in asthma pathophysiology include: