Baseline characteristics of the study participants stratified by children who had current asthma during the study period and children who did not [<i>n</i> (%)].

* P value was estimated based on Chi-square test or Fisher’s exact test. †Active maternal smoking during pregnancy or presence of a smoker in the home during pregnancy. ‡Active maternal smoking during the first year after delivery, current maternal smoking, or presence of a smoker in the home after delivery until the present time. §Having had a pet dog or cat after delivery until the present time. Size of the wheal produced by the cockroach antigen ≥3 mm and larger than size of the wheal produced by histamine. Baseline characteristics of the study participants stratified by children who had current asthma during the study period and children who did not [n (%)].