Prenatal exposure to DEHP and childhood wheeze and atopic dermatitis: The Hokkaido Study on the Environment and Children’s Health

Abstract

Background: It is concerned that exposure to phthalates, which are widely used in consumer products, might affect asthma and allergies among children. Although it is reported that DEHP in house dust was associated children’s allergies in cross-sectional study including our report, very few prospective studies have been reported the association between prenatal exposure to phthalates and children’s allergies. Methods: A total of 514 Japanese pregnant women agreed to participate in the Hokkaido Study in Sapporo, Japan between 2002 and 2005. Maternal blood sample were collected 23–35 weeks of gestation and MEHP was measured by GC/MS. Total IgE was measured from cord blood. Characteristics of mothers and children were obtained from medical birth record and questionnaires. The occurrence of wheeze and atopic dermatitis were assessed at age of 1.5 (n=384), 3.5 (n=324) and 7 years (n=266) using ISAAC questionnaire. Results: MEHP was detected from all samples and median concentration was 37.4 pmol/mL. The prevalence of wheeze and atopic dermatitis were 8.6% and 12.5% at 1.5 years and 24.7% and 28.3% at 1.5 years, and 16.5% and 21.4% at 7 years, respectively. There was no significant association between prenatal MEHP level and IgE in cord blood. Furthermore, we did not find any associations between prenatal MEHP level and children’s wheeze or atopic dermatitis at 1.5, 3.5, and 7 years. Conclusion: Prenatal DEHP exposure did not show adverse effects on infant IgE levels and children’s wheeze or atopic dermatitis. Adverse health effects of DEHP exposure on allergies might have strong impact on postnatal exposure rather than prenatal. However, only MEHP was measured to assess DEHP exposure in this study, therefore, other metabolites should be considered in further study.