Early life environmental exposures and children's growth : A longitudinal study evaluating prenatal exposure for endocrine disrupting chemicals and nutrition in relation to children's growth up to seven years of age

Abstract: Endocrine disrupting chemicals (EDCs) have the potential to disrupt the endocrine system in humans and animals with importance for health and development. Additionally, optimal nutrition during pregnancy is critical for fetal growth and pregnancy outcomes. However, further knowledge on the importance of EDC mixtures and nutrition, on birthweight and growth during childhood is needed. The overall aim of this thesis was to evaluate the associations between prenatal exposure to EDC mixtures and nutrition respectively, with birthweight, growth and body composition in early- and mid-childhood, and to determine if these associations differed by sex. Data from mother-child pairs in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study was analyzed, including 26 EDCs in prenatal urine and serum samples, children’s anthropometric and body composition measures up to seven years of age, and sociodemographic data from questionnaires and registers.Results suggest that higher prenatal exposure to EDC mixtures were associated with lower birthweight, and slower weight gain in early childhood, including a later peak growth velocity among girls. At 5.5 and 7 years of age, EDC mixtures were associated with lower BMI, less odds of overweight and less body fat among girls, but more body fat among boys at 7 years of age. Chemicals of concern in the mixtures were e.g., phthalates, bisphenols, perfluorinated alkyl substances (PFASs) and pesticides. Finally, maternal nutrition during pregnancy, i.e., better adherence to nutritional guidelines, was associated with more body fat for boys but less body fat for girls.In conclusion, prenatal exposure to both EDC mixtures and nutrition suggests to have an influence on birthweight, and children´s growth. Several of the found associations also differed by sex.