Thyroid Function Screening

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.