Measures
Achenbach & Rescorla
Behavioural and emotional problems of children at age 4 years were reported by parents using the Child Behaviour Checklist for ages 1.5–5 years (CBCL1½‐5) (Achenbach & Rescorla, The Behaviour Rating Inventory of Executive Function‐Preschool Version (BRIEF‐P) (Gioia et al., Women were visited once in each trimester of pregnancy and a wide range of information was recorded. Clinical and obstetric history was requested, including maternal age, parity and pregnancy planning. Anthropometric measurements (weight and height) were taken and body mass index was calculated. Dietary habits were assessed using a self‐administered food frequency questionnaire previously validated in our population (Rodríguez et al., In each trimester of pregnancy, blood samples were collected for biochemical determinations of Hb, SF and C‐reactive protein. Plasma polyunsaturated fatty acids (PUFAs) and serum vitamin D concentrations were quantified, because they are involved in brain development, so maternal levels during pregnancy may affect fetal neurodevelopment (Voltas et al., As for information about the children, the following data were recorded. At birth, sex, gestational age (calculated from the time since the first day of the last menstruation) and Apgar test score were obtained. Anthropometric measurements were recorded at birth and 40 days of age (length, weight and head circumference) and repeated at 4 years of age (weight and height). Similarly, the feeding mode was recorded at birth and 40 days of age and children's diet at 4 years of age was reported by parents using the same food frequency questionnaire as for participating women. Children's IQ was obtained at 4 years of age. All children were schooled by the time of the assessment.