Effects of prenatal and perinatal exposure to fine air pollutants and maternal fish consumption on the occurrence of infantile eczema.

BACKGROUND As there is a scarcity of evidence on potential hazards and preventive factors for infantile eczema operating in the prenatal period, the main goal of this study was to assess the role of prenatal exposure to fine particulate matter and environmental tobacco smoke (ETS) in the occurrence of infant eczema jointly with the possible modulating effect of maternal fish consumption. METHODS The study sample consisted of 469 women enrolled during pregnancy, who gave birth to term babies (>36 weeks of gestation). Among all pregnant women recruited, personal measurements of fine particulate matter (PM₂.₅) were performed over 48 h in the second trimester of pregnancy. After delivery, every 3 months in the first year of the newborn's life, a detailed, standardized, face-to-face interview was administered to each mother, in the process of which a trained interviewer recorded any history of infantile eczema and data on potential environmental hazards. The estimated risk of eczema related to higher prenatal exposure to fine particulate matter (PM₂.₅ > 53.0 μg/m³) and postnatal ETS as well as the protective effect of maternal fish intake were adjusted for potential confounders in a multivariable logistic regression model. RESULTS While the separate effects of higher prenatal PM₂.₅ and postnatal ETS exposure were not statistically significant, their joint effect appeared to have a significant influence on the occurrence of infantile eczema [odds ratio 2.39, 95% confidence interval (CI) 1.10-5.18]. With maternal fish intake of more than 205 g/week, the risk of eczema decreased by 43% (odds ratio 0.57, 95% CI 0.35-0.93). The incidence rate ratio (IRR) for eczema symptoms, estimated from the Poisson regression model, was increased with both higher exposure to prenatal PM₂.₅ and postnatal ETS (IRR 1.55, 95% CI 0.99-2.44) and in children of atopic mothers (IRR 1.35, 95% CI 1.04-1.75) but was lower in girls (IRR 0.78, 95% CI 0.61-1.00). The observed preventive effect of fish consumption on the frequency of eczema symptoms was consistent with the results of the logistic analysis (IRR 0.72, 95% CI 0.52-0.99). CONCLUSIONS The findings indicate that higher prenatal exposure to fine particulate matter combined with postnatal exposure to ETS may increase the risk of infant eczema, while maternal fish intake during pregnancy may reduce the risk of infantile eczema.