In utero exposure to pets is associated with asthma and wheezing in Mexican American children

Objective: To examine the associations of in utero and early life exposure to cats/dogs and birds with the risk of lifetime doctor-diagnosed asthma and other respiratory conditions in a sample of Mexican American (MA) children 4–18 years of age. Methods: This study is a population-based cross-sectional investigation of 1816 MA children. We conducted multiple logistic models examining the relationship of asthma and wheezing with exposures to cats/dogs and birds in utero, infancy and at the time of the survey adjusted for country of birth, family history of asthma/allergies, antibiotics use in infancy and other covariates. Results: In adjusted analyses, in utero exposure to cats/dogs and birds jointly was associated with increased odds of asthma (adjusted odds ratio (aOR): 2.89; 95% confidence interval (CI): 1.34–6.23), ever wheezing (aOR: 1.96; 95% CI: 1.11–3.46) and current exercise-induced wheezing (aOR: 3.16; 95% CI: 1.27–7.85) compared to children not exposed to these pets in utero. Children who were exposed to both cats/dogs and birds in utero had an elevated, albeit statistically non-significant, odds of current wheezing. Exposures in infancy and at the time of the survey to cats/dogs and birds were not associated with asthma or wheezing. Conclusions: In utero exposure to pets might be associated with an increased risk of asthma and respiratory conditions in a sample of non-affluent MA children.