Background/aim There are concerns neuro-developmental due to exposure to endocrine disrupting chemicals. Previous epidemiological studies have mainly focused on phthalate metabolites and bisphenol A. Our study aimed to assess associations between in-utero exposure to the afore mentioned compounds and other ubiquitous phenolic compounds and the Intelligence Quotient (IQ) of boys at 5–6 years.

Methods In 452 mother-son dyads from the French EDEN cohort, we measured 11 phthalate metabolites and 9 phenolic compounds (4 parabens, benzophenone-3, bisphenol A, 2 dichlorophenols and triclosan) in spot urine samples collected between 22 and 29 gestational weeks. Verbal and performance IQ of children was assessed at 5–6 years by a psychologist using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). We used adjusted Structural Equation Models (SEM) and the Benjamini and Hochberg false discovery rate (FDR) correction to assess the associations between maternal urine phenol and phthalate metabolite concentrations considered simultaneously and the boys’ IQ.

Results No phenol or phthalate metabolite concentration was negatively associated with child verbal or performance IQ (p-values≥0.09). Mono (3-carboxypropyl) phthalate tended to be associated with increased verbal IQ (β=0.136, 95% confidence interval, 0.01; 0.27) but this association disappeared after correction for multiple comparison (corrected p- 64 value, 0.71).

Conclusion To our knowledge, our study is the first to consider developmental exposure to parabens, dichlorophenols, triclosan and benzophenone-3 in relation to child cognitive development. Our findings did not suggest an inverse association between in-utero phenols and phthalates exposure and child verbal and performance IQ.