Pre- and postnatal risk factors in relation to allergic rhinitis in school-aged children in China.

Abstract

OBJECTIVE: The objective of this study was to investigate the relationship between prenatal and postnatal risk factors and the prevalence of allergic rhinitis (AR) in Chinese children of specific ages. STUDY DESIGN: This study was a cross-sectional survey. Students from 8 metropolitan cities in China were studied in November and December, 2005. There were 20,803 elementary-school Chinese children (49.6% boys, mean age, 9.19 years) enrolled. Questions from the standard questionnaire of the International Study of Asthma and Allergies in Children were completed to enable us to examine the pattern of current AR. The potential confounders and pre-and postnatal risk factors were analyzed using logistic regression. RESULTS: The overall prevalence of AR was found in this study to be 9.8%. After adjusting for several likely confounders, there was a higher likelihood of AR in school-aged children who were not exclusively breastfed in the first 4 months of their lives (odds ratio [OR]: 1.28; 95% confidence interval [CI]: 1.16-1.41), children who were born post-term (OR: 1.34; 95% CI: 1.12-1.60), children delivered by cesarean section (OR: 1.07; 95% CI: 1.00-1.19), or children born to mothers who experienced depressive symptoms during the pre- and postnatal periods (OR: 1.28; 95% CI: 1.15-1.42). CONCLUSIONS: AR in school-aged children was found to be associated with pre- and postnatal events. These findings indicate that strategies to reduce exposure to risk factors during pre- and postnatal periods for childhood allergies might be warranted.