Chemicals in pregnancy linked to child brain development problems
A major Swedish study finds that common industrial chemicals exposure during pregnancy may harm children's brain development, with effects potentially differing between boys and girls. The research suggests maternal thyroid disruption could be a key mechanism, signaling significant implications for occupational health policy and product regulation across industries.
Originaltitel: The importance of prenatal environment for children’s neurodevelopment: Epidemiological studies on endocrine disrupting chemicals and stress
<p>The first gestational weeks are essential for the normal development of the brain. While this is an intricate process between genes and environment, certain environmental factors, such as endocrine disrupting chemicals (EDC) and their mixtures, and adverse life events (ALE), may disrupt this process. However, more knowledge is needed on how these environmental factors contribute to neurodevelopmental outcomes. It is also unknown if maternal thyroid hormones might mediate the associations and how children’s play behaviour is associated with neurodevelopmental outcomes.</p><p>The aim of the thesis is to explore the importance of prenatal exposure to EDCs and their mixtures and ALE for children’s neurodevelopmental outcomes, examine if maternal thyroid mediates such associations, explore neurodevelopmental outcomes in relation to play behaviour, and identify whether associations differ between boys and girls.</p><p>Data from the Swedish Environmental Longitudinal Mother and child Asthma and allergy study have been used in this thesis. Urine and serum samples have been collected from the mother during early pregnancy to measure the concentrations of EDCs and thyroid hormones. Data on ALEs were collected by questionnaire when the children were 4 years old, and behavioural outcomes and cognitive function as well as play behaviour were assessed when children were 7.5 years old using validated instruments.</p><p>Results show that prenatal exposure to EDC mixtures was associated with behavioural difficulties in children, with differences observed between boys and girls. Maternal thyroid function emerged as a potential biological mechanism underlying these associations. Furthermore, ALEs during pregnancy were linked to behavioural, but not cognitive outcomes. Lastly, children's play behaviour was associated with behavioural outcomes.</p><p>In conclusion, EDCs and ALEs are associated with neurodevelopmental outcomes, and there are co-occurrences between children’s play and neurodevelopmental outcomes.</p>