Box 1.

At-risk groups of hypo- and hyperthyroidism requiring thyroid function screening: recommended criteria for thyroid function test screening in prenatal women1

  • Age ≥30 years old

  • Family history of autoimmune thyroid disease or hypothyroidism

  • Presence of a goitre

  • Thyroid antibodies, primarily thyroid peroxidase antibodies

  • Symptoms or clinical signs suggestive of thyroid hypofunction

  • History of type 1 diabetes or other autoimmune disorders

  • History of infertility

  • Prior history of miscarriage or preterm delivery

  • Previous therapeutic head or neck irradiation or prior thyroid surgery

  • Currently receiving levothyroxine replacement

  • Living in a region with presumed iodine deficiency