Relationship between mode of delivery in childbirth and prevalence of allergic diseases in Korean children

PURPOSE We tested the hypothesis that cesarean section might increase the risk for allergic diseases compared to vaginal delivery, by depriving the newborn of exposure to maternal microflora. METHODS We evaluated the prevalence of allergic diseases, allergic inflammation, and allergic sensitization according to mode of delivery for 279 Korean children aged </=16 years. Data were extracted from medical records and a questionnaire filled out by parents. Logistic regression was used to determine the association between cesarean section and the outcomes of interest. RESULTS Of the 279 children, 179 (62.6%) were delivered vaginally and 100 (37.4%) by cesarean section. There were no differences in the prevalence of allergic diseases, allergic inflammation, or allergic sensitization according to mode of delivery. Children born by cesarean section had no higher risk of allergic disease than those delivered vaginally, regardless of a parental history for allergic disease. Adjusted odds ratios (95% confidence intervals) for cesarean section compared to vaginal delivery were not statistically significant for any outcome considered: asthma, 0.76 (0.37-1.57), allergic rhinitis, 1.14 (0.61-2.10), atopic dermatitis, 1.01 (0.59-1.71). CONCLUSIONS Delivery by cesarean section may not be associated with the subsequent development of asthma, allergic rhinitis, or atopic dermatitis in Korean children.