Demographics
Statistically significant differences were observed in gestational age at birth, maternal age at birth, and SHS exposure during the first year of life between the prenatally exposed and the non-exposed groups (Table 1). No other differences were found, including in parental history of allergic diseases. Except for maternal age at birth, mode of delivery, and daycare attendance during the first year of life, no significant differences regarding general characteristics were observed between the participants whose data were and were not included in the analysis (Supplementary Table 1).