Association between prenatal exposure to air pollution and risk of Kawasaki disease in young children of South Korea: Big children's environmental health study.

Although recent studies have suggested an association between air pollution and Kawasaki disease (KD), evidence regarding prenatal exposure and subsequent KD risk in children remains limited. This study aimed to evaluate the association between prenatal air pollution exposure and KD incidence in children. We used the Big CHildren's ENvironmental health Study covering mother-child pairs based on the National Health Information Database. We defined KD onset using the tenth revision of the International Classification of Diseases (M30.3) and immunoglobulin prescriptions. We used a multivariate Cox proportional hazards model to evaluate the association between prenatal air pollution exposure (fine particulate matter [PM2.5], particulate matter [PM10], sulfur dioxide [SO2], nitrogen dioxide [NO2], and ozone [O3]) and KD in children. The model was adjusted for maternal age, child sex, income level, maternal occupation, birth season, birth year, and region. Hazard ratios (HRs) and 95% confidence intervals (CIs) were evaluated per interquartile range increase in exposure to PM2.5, PM10, SO2, NO2, and O3. We analyzed 1624,230 mother-child pairs and identified KD onset in 13,126 children (0.8%). Prenatal exposure to PM10, SO2, and NO2 during the second and third trimesters, as well as across the entire pregnancy, was associated with an increased risk of KD, with the strongest associations observed during the third trimester (PM2.5: 1.046, 95% CI: 1.007-1.087; PM10: 1.104, 95% CI: 1.061-1.149; SO2: 1.052, 95% CI:1.117-1.153; NO2: 1.117, 95% CI: 1.082-1.153). We found that exposure to air pollution during pregnancy was positively associated with KD risk in children.