| Clinical criteria |
| Absence of thyroid disease, no current or previous treatment with antithyroid drugs or L-T4, no history of 131I therapy or thyroidectomy |
| No use of potentially interfering medications such as dopaminergic agonists or antagonists, neuroleptics, corticosteroids, estrogen, amiodarone, interferon, lithium, anticonvulsants, metformin, octreotide; or recent (in the past 8 weeks) exposure to iodinated contrast agents |
| No history of head and neck external radiotherapy |
| Absence of type 1 diabetes or other autoimmune diseases |
| No family history of thyroid disease |
| Absence of goiter or any palpable thyroid anomaly |
| Absence of ophthalmopathy |
| Complementary criteria: ≤ 12 weeks gestation and TPOAb negative |
