Sociodemographic information was collected using an interview-administered questionnaire, including information on age, education, income, alcohol consumption, smoking, drug use, occupational and recreational exposure to chemicals, medical history, familial history of hypothyroidism, use of medication, and number of dental amalgam fillings.

Height and weight were measured by a nurse and used to calculate body mass index.

At this visit, maternal blood was collected for analysis of PBDEs, PCBs, lipids profile, thyroid homones and metals (Mn, Pb, Hg, Se, Cd). Urine was collected for iodine and cotinine analysis and a hair sample was also collected.

Data on maternal health and obstetrical history, medication use, and delivery were obtained from medical records.

A questionnaire collected information about medical and obstetrical history and smoking and drinking during pregnancy.

Height and weight were measured by a nurse and used to calculate body mass index.

At delivery, maternal blood was collected for analysis of PBDEs, PCBs, lipids profile, thyroid hormone and metals (Mn, Pb, Hg, Se, Cd). Urine was collected from the mother for iodine and cotinine analysis. A hair sample was also collected. Finally, placenta and breast milk samples were collected.

Data on maternal health and obstetrical history, medication use, and delivery were obtained from medical records.

At the 6-7 years follow-up, sociodemographic information was collected using an interview-administered questionnaire, including information on age, education, income, alcohol consumption, smoking, drug use, occupational and recreational exposure to chemicals, medical history, familial history of hypothyroidism, use of medication, and number of dental amalgam fillings.

Abstract reasoning was assessed using the Raven’s Matrices.

Height and weight were measured by a nurse and used to calculate body mass index. Impedance measurements were also performed.

At this visit, maternal blood was collected for analysis of PBDEs and halogenated substitutes, PCBs, lipids profile, thyroid homones and metals (Mn, Pb, Hg, Se, Cd).

At the 8-10 years follow-up, sociodemographic information was collected using an interview-administered questionnaire, including information on age, education, income, alcohol consumption, smoking, drug use, occupational and recreational exposure to chemicals, medical history, familial history of hypothyroidism, use of medication, and number of dental amalgam fillings.

Cognitive functioning was assessed using the Wechsler Adult Intelligence Scale (WAIS-IV).

Height and weight were measured by a nurse and used to calculate body mass index. Impedance measurements were also performed.

At delivery, lenght and weight were measured by a nurse. Apgar score and other complications were also collected.

Umbilical-cord blood was collected for analysis of PBDEs, PCBs, lipids profile, thyroid hormone and metals (Mn, Pb, Hg, Se, Cd). A hair sample was also collected. Finally, meconium and placenta samples were collected.

At the 2 years follow-up, information about sociodemographics, nutrition (including breastfeeding and formula use), and anthropometric measurements was collected by questionnaire. Information on health-related quality of life was collected using the Child Health Questionnaire. Information about the development of social, self-help, motor, language, letter and number skills, and presence of symptoms and behavior problems was also collected through the Child Development Inventory.

Hair and nails samples were collected.

At the 6-7 years follow-up, cognitive function was assessed using the Wechsler Intelligence Scale for Children (WISC-IV), the Developmental NEuroPSYchological Assessment (NEPSY-II), the Test of Everyday Attention for Children (TEA-Ch) and the Developmental Coordination Disorder Questionnaire (DCDQ).

Height and weight were measured by a nurse and used to calculate body mass index. Impedance measurements were also performed.

At this visit, blood was collected for analysis of PBDEs and halogenated substitutes, PCBs, lipids profile, thyroid homones and metals (Mn, Pb, Hg, Se, Cd). Urine was collected for cotinine analysis. A stool sample was collected for analysis of PBDEs and halogenated substitutes, metals (Mn, Pb, Hg, Se, Cd), pesticides, antibiotics and other drugs and gut microbiome composition (16S RNA and metatranscriptomics). Hair, nails and tooth samples were also collected.

At the 8-10 years follow-up, information was collected using an interview-administered questionnaire to the parents including information on nutrition using a Food Frequency Questionnaire (FFQ), autism using the Empathy/Systemizing Quotient (EQ-SQ) and Autism Spectrum Quotient (AQ), childhood ADHD using the Wender Utah Rating Scale (WURS), behaviors and emotions using the Behavior Assessment System for Children (BASC-3), executive function behaviors at home and at school using the Behavior Rating Inventory of Executive Function (BRIEF), and depression, anxiety, anger, disruptive behaviour and self-concept using the Beck Youth Inventory. Hand dominance information was also collected.The Vanderbilt ADHD rating was completed by both the parents and teachers.

Cognitive function was assessed using the Conners' Continuous Performance Test (Conners CPT), the Wechsler Intelligence Scale for Children (WISC-V), he Developmental NEuroPSYchological Assessment (NEPSY-II), the Pegboard Test, and the Finger-Taping Task.

Height and weight were measured by a nurse and used to calculate body mass index. Impedance measurements were also performed. Physical development was assessed using the Tanner Scale. A brain MRI was also performed (anatomic MRI, task-based fMRI, resting state functional connectivity MRI, diffusion MRI).

At this visit, blood was collected for analysis of PBDEs and halogenated substitutes, PCBs, lipids profile, thyroid and sexual homones, and metals (Mn, Pb, Hg, Se, Cd). Urine was collected for cotinine analysis. A stool sample was collected for analysis of PBDEs and halogenated substitutes, pesticides, antibiotics and other drugs and gut microbiome composition (16S RNA and metatranscriptomics). Hair, tooth and dust samples were also collected.