Prevalence of asthma and wheezing in public schoolchildren: association with maternal smoking during pregnancy

Background: Asthma is the most common chronic disease in childhood. The prevalence of asthma is especially high in inner city children. The occurrence of asthma may be associated with many environmental factors, including involuntary exposure to maternal smoking. Objectives: This study reports prevalence of asthma and wheezing in a sample of public school students in Chicago and examines the association between maternal smoking during pregnancy and childhood asthma. Methods: A total of 705 fifth grade students from 13 public schools participated in the study. A slightly modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered in classrooms to assess students' wheezing and asthma prevalence. Results: Overall, 34.5% of children reported ever wheezing, 28.9% reported wheezing in the past year, 21.1% reported exercise-related wheezing in the past year, 23.6% reported physician-diagnosed asthma, 16.1% reported taking asthma or wheezing medication in the past 2 weeks, and 15.2% reported visiting emergency rooms for treatment of asthma in the past year. After adjusting for confounding variables in a logistic model, maternal smoking during pregnancy was significantly associated with children's asthma (adjusted odds ratio = 1.9; 95% confidence interval: 1.1 to 3.5). Conclusions: This study reports high prevalence of asthma and wheezing among the students and suggests that maternal smoking during pregnancy may increase the risk of asthma in children.