Internal medicine

Neuroscience

Disease

Thyroid disease

Brain development

Physiology

Thyroid

Bioinformatics

Biology

Offspring

Epistemology

Endocrinology

Philosophy

Estrogen

Pregnancy

Mechanism (biology)

Endocrine system

Genetics

Hormone

Medicine

Endocrine Connections

This review covers recent findings on the main categories of thyroid hormone-disrupting chemicals and their effects on brain development. We draw mostly on epidemiological and experimental data published in the last decade. For each chemical class considered, we deal with not only the thyroid hormone-disrupting effects but also briefly mention the main mechanisms by which the same chemicals could modify estrogen and/or androgen signalling, thereby exacerbating adverse effects on endocrine-dependent developmental programmes. Further, we emphasize recent data showing how maternal thyroid hormone signalling during early pregnancy affects not only offspring IQ, but also neurodevelopmental disease risk. These recent findings add to established knowledge on the crucial importance of iodine and thyroid hormone for optimal brain development. We propose that prenatal exposure to mixtures of thyroid hormone-disrupting chemicals provides a plausible biological mechanism contributing to current increases in the incidence of neurodevelopmental disease and IQ loss.

Thyroid-disrupting chemicals and brain development: an update