Table 2. Questionnaires, test and biological samples collected before the 7 years old of children.

Previous phases of the study	Questionnaires, test or biological samples	Information collected
During pregnancy	Short questionnaire	It was designed to identify any excluding conditions and to provide a quick assessment of parent’s socio-demographic information and maternal frequency of consumption of food items (eg, fish, vegetables) and smoking status.
	Raven’s Progressive Matrices Test	Evaluation of maternal intelligence.
	Maternal Hair	Measurement of: THg and MeHg.
	Maternal Urine	Measurement of THg.
	Maternal blood	Genotyping analysis. Measurement of: THg, MeHg, As, Se, Mn, Cu, Zn, Pb, Cd and PUFAs (from serum).
At delivery	Cord blood	Genotyping analysis. Measurement of: THg, MeHg, As, Se, Mn, Cu, Zn, Pb and Cd.
Within the first month after delivery	Long questionnaire	It was designed to collect: sociodemographic and health status information on mothers and their family, information on pregnancy and delivery and health status of the newborn child, a detailed residential and occupational history of the mother, maternal smoking, maternal drinking, and general dietary habits (through a detailed food frequency assessment of her consumption of 138 food items adapted from a validated food frequency questionnaire).
	Breast milk	Measurement of: THg, MeHg, As, Se, Mn, Cu, Zn, Pb and Cd.
At 18 and at 40 months of age of children	Supplementary questionnaire	It assessed changes in residence, maternal marital and occupational status, anthropometric measures (weight and height) and developmental milestones of the child, breastfeeding history, child intake of fish, diseases, and day-care attendance.
	Bayley Scales of Infant and Toddler Development Third Edition (BSID-III)	Evaluation of child neurodevelopment.
Between 18 and 40 months of age of children	Home Observation for Measurement of the Environment questionnaire (HOME)	Evaluation of family environment (ie, how parents and children interact in the home context)