Relationship between prenatal antibiotic use and asthma in at-risk children.

Background: Asthma prevalence has doubled in developed countries during the past 30 years. Pre- and perinatal events are essential in shaping the development of the immune system and systemic antibiotic use during this time could alter the maternal or placental microbiome, leading to an increase in the child's risk of developing asthma. Objective: To determine whether prenatal antibiotic use is associated with asthma and wheezing in children at risk for asthma. Methods: Using data from a randomized education intervention of families at risk for asthma from 1998 followed through 2009 in urban Chicago, asthma was defined as ever having a physician asthma diagnosis by year 3 and wheezing in the third year. Logistic regression models controlling for confounders investigated the effect of antibiotic use during pregnancy on these outcomes. Results: After adjustment, prenatal antibiotic use was a risk factor for asthma (odds ratio 3.1, 95% confidence interval 1.4-6.8) but was only weakly associated with wheezing (odds ratio 1.8, 95% confidence interval 0.9-3.3). Analyses of the effects of timing of prenatal antibiotic use on asthma and wheezing showed the relation remained consistent for antibiotic use later in pregnancy, but the outcomes were not associated with antibiotic use in the first trimester. Conclusion: This study suggests prenatal antibiotic use might be associated with the development of asthma in children at risk for asthma. Although the relation with prenatal antibiotics does not hold for wheezing in this study, there might be a trend that could be delineated further within a larger cohort study. (C) 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.