Prenatal exposure to bisphenol A and phthalates and behavioral problems in children at preschool age: the Hokkaido Study on Environment and Children's Health

BACKGROUND@#Studies reported adverse behavioral development including internalizing and externalizing problems in association with prenatal exposure to bisphenol A (BPA) and phthalates; however, findings were not sufficient due to using different assessment tools and child ages among studies. This study aimed to examine associations between maternal serum levels of BPA and phthalate metabolites and behavioral problems at preschool age.@*METHODS@#The Strengths and Difficulties Questionnaire (SDQ) was used to assess behavioral problems at 5 years of age. BPA and phthalate metabolite levels in the first trimester maternal serum was determined by LC-MS/MS for 458 children. Variables used for adjustment were parental ages, maternal cotinine levels, family income during pregnancy, child sex, birth order, and age at SDQ completed.@*RESULTS@#The median concentrations of BPA, MnBP, MiBP, MEHP, and MECPP, primary and secondary metabolites of phthalates, were 0.062, 26.0, 7.0, 1.40, and 0.20 ng/ml, respectively. MECPP level was associated with increase conduct problem risk (OR = 2.78, 95% CI 1.36-5.68) overall and the association remained after child sex stratification, and odds ratios were increased with wider confidence interval (OR = 2.85, 95% CI 1.07-7.57 for boys, OR = 4.04, 95% CI 1.31-12.5 for girls, respectively). BPA, ∑DBP (MnBP + MiBP), and ∑DEHP (MEHP+MECPP) levels were not associated with any of the child behavioral problems.@*CONCLUSIONS@#Our analyses found no significant association between BPA or summation of phthalate metabolite levels and any of the behavioral problems at 5 years of age but suggested possible association between MECPP levels and increased risk of conduct problems.

Retrospectivein utero exposure assessment of PCBs using preserved umbilical cords and its application to case-control comparison

<p><b>OBJECTIVES</b>The aim of this study is to assess preserved umbilical cords as chemical exposure media to investigatein utero chemical exposure. Furthermore, we aim to apply preserved umbilical cords to retrospective studies of the relationship betweenin utero chemical exposure and neurodevelopment disorders.</p><p><b>METHODS</b>Two sets of preserved umbilical cord samples were analyzed for exposure to polychlorinated biphenyls (PCBs): one composed of samples from 20 healthy Japanese subjects and the other set included samples from 17 autistic patients and 7 healthy sibling of theirs.</p><p><b>RESULTS</b>The possibility of external PCBs contamination during storage of preserved umbilical cord samples was found, and due to this problem, the study design should be limited to the comparison between PCBs concentration in preserved cord samples from autistic patients and that in those from their sibling. Total PCBs concentrations in preserved cords from autistic patients and their control siblings were compared and we found no statistically significant difference between them (Wilcoxon signed rank test, p>0.05).</p><p><b>CONCLUSIONS</b>The association between autism andin utero PCBs exposure was not clarified in this study; however, retrospective studies such as a case-control study of siblings using preserved umbilical cords can be a method of choice for examining the possible relationship betweenin utero chemical exposure and child hood disorders.</p>

Retrospective \it{In Utero} Exposure Assessment of PCBs Using Preserved Umbilical Cords and Its Application to Case-Control Comparison

Objectives: The aim of this study is to assess preserved umbilical cords as chemical exposure media to investigate in utero chemical exposure. Furthermore, we aim to apply preserved umbilical cords to retrospective studies of the relationship between in utero chemical exposure and neurodevelopment disorders. Methods: Two sets of preserved umbilical cord samples were analyzed for exposure to polychlorinated biphenyls (PCBs): one composed of samples from 20 healthy Japanese subjects and the other set included samples from 17 autistic patients and 7 healthy siblings of theirs. Results: The possibility of external PCBs contamination during storage of preserved umbilical cord samples was found, and due to this problem, the study design should be limited to the comparison between PCBs concentration in preserved cord samples from autistic patients and that in those from their sibling. Total PCBs concentrations in preserved cords from autistic patients and their control siblings were compared and we found no statistically significant difference between them (Wilcoxon signed rank test, p>0.05). Conclusions: The association between autism and in utero PCBs exposure was not clarified in this study; however, retrospective studies such as a case-control study of siblings using preserved umbilical cords can be a method of choice for examining the possible relationship between in utero chemical exposure and childhood disorders.