Prenatal PM(2.5) affects atopic dermatitis depending on maternal anxiety and gender: COCOA study

BACKGROUND: The prevalence of atopic dermatitis (AD) is increasing worldwide. Prenatal particulate matter with an aerodynamic diameter <2.5 μm (PM(2.5)) and maternal anxiety during pregnancy has been suggested as a potential causes of AD. This study investigated the effects of prenatal PM(2.5) and maternal anxiety on AD and identified the critical period of PM(2.5) exposure for AD in infants. METHODS: This study included 802 children from the COCOA birth cohort study with follow‐up data at 1 year of age. PM(2.5) was estimated by land‐use regression models and prenatal anxiety was measured with a questionnaire. AD was diagnosed by doctor at 1 year of age. Logistic regression analysis and Bayesian distributed lag interaction models were applied. RESULTS: Higher PM(2.5) during the first trimester of pregnancy, higher prenatal maternal anxiety, and male gender were associated with AD at 1 year of age (adjusted odds ratio [aOR] and 95% confidence interval [CI]: 1.86 [1.08–3.19], 1.58 [1.01–2.47], and 1.54 [1.01–2.36], respectively). Higher PM(2.5) during the first trimester and higher maternal anxiety during pregnancy showed an additive effect on the risk of AD (aOR: 3.13; 95% CI: 1.56–6.28). Among boys exposed to higher maternal anxiety during pregnancy, gestational weeks 5–8 were the critical period of PM(2.5) exposure for the development of AD. CONCLUSIONS: Higher PM(2.5) exposure during gestational weeks 5–8 increased the probability of AD in infancy, especially in boys with higher maternal anxiety. Avoiding PM(2.5) exposure and maternal anxiety from the first trimester may prevent infant AD.