Prenatal Exposure to Phthalate Esters and Behavioral Syndromes in Children at 8 Years of Age: Taiwan Maternal and Infant Cohort Study

BACKGROUND: Few studies have shown an association between prenatal phthalate exposure and adverse effects on neurodevelopment and behavior in young children. OBJECTIVES: We aimed to assess the relationship between prenatal exposure to phthalate esters and behavior syndromes in children at 8 years of age. METHODS: A total of 122 mother-child pairs from the general population in central Taiwan were studied from 2000 to 2009. Mono-methyl phthalate (MMP), mono-ethyl phthalate (MEP), monobutyl phthalate (MBP), mono-benzyl phthalate (MBzP), and three di-(2-ethylhexyl)phthalate (DEHP) metabolites-mono-2-ethylhexyl, mono-2-ethyl-5-hydroxyhexyl, and mono-2-ethyl-5-oxohexyl phthalates (MEHP, MEHHP, and MEOHP)-were measured in maternal urine collected during the third trimester of pregnancy using liquid chromatography-electrospray ionization-tandem mass spectrometry. Behavioral syndromes of children at 8 years of age were evaluated using the Child Behavior Checklist (CBCL). Associations between log(10)-transformed creatinine-corrected phthalate concentrations and standardized scores of the CBCL were estimated using linear regression models or multinomial logistic regressions with adjustments for potential confounders. RESULTS: Externalizing problem scores were significantly higher in association with a 1-unit increase in log10-transformed creatinine-corrected concentrations of maternal MBP (beta = 4.29; 95% CI: 0.59, 7.99), MEOHP (beta = 3.74; 95% CI: 1.33, 6.15), and MEHP (beta = 4.28; 95% CI: 0.03, 8.26) after adjusting for the child's sex, intelligence, and family income. Meanwhile, MBP and MEOHP were significantly associated with Delinquent Behavior and Aggressive Behavior scores. The same pattern was found for borderline and/or clinical ranges. CONCLUSIONS: Our findings suggest positive associations between maternal DEHP and dibutyl phthalate (DBP) exposure and externalizing domain behavior problems in 8-year-old children.