Last reviewed 01/2018

Aetilogy of congenital hypothyroidism can be:

  • permanent congenital hypothyroidism
    • primary hypothyroidism - the commonest causes include
      • thyroid agenesis
      • thyroid dysgenesis - due to a developmental anomaly of the thyroid gland e.g. - ectopic thyroid or hypoplastic thyroid as a result of a failure of normal descent of the thyroid in development
      • thyroid dyshormonogenesis – due to impaired hormone production
    • central or secondary hypothyroidism 
      • most commonly presents as a part of a disorder causing congenital hypopituitarism
      • isolated TSH deficiency
      • thyrotropin-releasing hormone deficiency or resistance
  • peripheral hypothyroidism
    • resistance to thyroid hormone
    • defect in thyroid hormone transport
  • transient congenital hypothyroidism
    • maternal ingestion of antithyroid drugs
    • transfer of maternal TSH receptor blocking antibodies through the placenta
    • iodine deficiency – both in mother and neonate (1)

There is an association with Down's syndrome (1)