Endocrine disrupting chemicals in the environment and infant neurobehavioral development

Abstract

The research of my PhD program was part of the Life MILCH Project, which is a longitudinal pilot study aiming to determine the association between mothers’ life and nutritional habits, maternal levels of EDCs, EDCs in in breastmilk or formula, and infants’ growth and neurobehavioral development in the first year of life in two geographical area: Emilia Romagna and Sardinia. Endocrine Disrupting Chemicals (EDCs) are man-made environmental chemicals present in everyday environment and food (e.g., phthalates, bisphenol A, Heavy metals, Glyphosate, Dioxin) that can disrupt the programming of endocrine signalling pathways during development, resulting in adverse effects that may not be apparent until much later in life. Maternal exposure to EDCs during pregnancy and lactation results in fetal and neonatal exposure via utero and breastmilk. Exposure to EDCs (in utero or by breastfeeding) has been associated to impairment of reproductive, neurobehavioral, metabolic, and immunologic functions. In the present study 245 pregnant women were enrolled at Parma University Hospital and subjected to 2 questionnaires on lifestyle and nutritional habit (Q#1, Q#2) and to urine collection. At birth, 1, 3, 6, and 12 months of age, infants’ growth and neurobehavioral development were assessed by a clinical exam and different tests: Visual Preference Paradigm, Face-to-Face-Still-Face, Fagan test, Barrier Task and the Bayley III Scale. Pre- and post-natal infant exposure to EDCs was assessed through questionnaires about maternal and infant lifestyle and nutritional habits and by the analysis of biological samples (maternal and infant urine, plasma, breastmilk or formula). Maternal lifestyle, nutritional and clinical information before and after pregnancy will be correlated with EDC levels in biological samples and infants’ growth and neurodevelopment. The longitudinal data analyses presented here are based on a sub-group of 88 mother-infant dyads who took part to the follow-up visits both for evaluation of physical and neurobehavioral development at 1 and 3 months of life (Visual Preference Paradigm and Face-to-Face-Still-Face), and for the neurodevelopmental assessment at 6 and 12 months of life (Bayley test). A sub-sample of 22 mother-infant dyads, of which the chemical data have been obtained, were selected to analyze the interaction effects between specific EDCs, namely: (i) Bisphenols (BPs) and Parabens (PBs) concentration levels in breastmilk and maternal urine at the recruitment, 1 and 3 months after birth with infants growth parameters and neurodevelopmental outcomes; (ii) Maternal-infant lifestyle and nutritional habits with infants growth parameters and neurodevelopmental outcomes. Preliminary results show significant interaction effects between pre- and post- natal BPs and PBs concentration levels in breastmilk and maternal urine, and the infant growth and neurodevelopment. More specifically, anogenital distance, body weight, socioemotional stress response, and neurodevelopmental areas influence were found. Finally, there were significant interaction effects between pre- and post-natal maternal and infant lifestyle and nutritional habits, and infant anogenital distance, body weight, socioemotional stress response, cognitive and motor developmental areas. The small sample size, due to the Covid-19 pandemic related delays in the sample collection and analysis, prevented a robust statistical assessment. However, these preliminary results suggest that infant neurobehavioral outcomes may be affected by exposure to EDCs and may provide early biomarkers of effects in relation to maternal lifestyle and nutritional habits. Further analysis will allow to better understand the possible associations between maternal lifestyle and nutritional habits, EDCs exposure via breastmilk and infant neurodevelopment and growth in order to develop a risk assessment model of EDCs exposure and effects.