For initial thyroid function screening in nonpregnant individuals, order Thyroid Stimulating Hormone with reflex to Free Thyroxine. For pregnant women, the optimal method of thyroid screening is Thyroxine, Free (Free T4), rather than TSH/free T4 combination. Triiodothyronine, Free (Free T3), and Triiodothyronine, Total (Total T3), should be ordered only for specific circumstances (eg, abnormal TSH/normal free T4 and suspicion of thyroid disease). Thyroid panels containing obsolete tests such as T3 Uptake and total T4 should not be ordered.
Alexander EK, Pearce EN, Brent GA, et al. 2017 Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and the postpartum. Thyroid. 2017;27(3):315-389.
Carney LA, Quinlan JD, West JM. Thyroid disease in pregnancy. Am Fam Physician. 2014;89(4):273-278.
Garber JR, Cobin RH, Gharib H, et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocr Pract. 2012;18(6):988-1028.
De Groot L, Abalovich M, Alexander EK, et al. Management of thyroid dysfunction during pregnancy and postpartum: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2012;97(8):2543-2565.