Statistical analyses
The characteristics of the mothers and their children were summarized according to the delivery mode. A chi-squared test was used to compare categorical variables. Multiple logistic regression was performed to determine the risks of asthma, atopic dermatitis, wheezing, and eczema associated with cesarean delivery by calculating the odds ratios (ORs), which were adjusted for the aforementioned confounders, and 95% confidence intervals (CIs). We initially adjusted for perinatal and socioeconomic factors. We then adjusted for perinatal, socioeconomic, and postnatal factors. Finally, we estimated the association between elective and emergency cesarean delivery (vs. vaginal delivery) and the risks of asthma, atopic dermatitis, wheezing, and eczema. Statistical analyses were performed using Stata, version 15.0 (Stata Corporation LLC, College Station, TX, USA). P -values < 0.05 were considered statistically significant.