ARUP's Laboratory Test Directory

Thyroid Stimulating Hormone with reflex to Free Thyroxine : 2006108

Mnemonic: TSHREFLEX

Ordering Recommendation: Use to assess thyroid function. Includes reflex to free thyroxine for thyroid stimulating hormone results outside of the reference range.
Methodology: Quantitative Electrochemiluminescent Immunoassay
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Collect: Serum separator tube or plasma separator tube. Also acceptable: Lavender (EDTA) or green (sodium or lithium heparin).

Specimen Preparation: Allow specimen to clot completely at room temperature. Separate serum or plasma from cells ASAP or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Grossly hemolyzed specimens.

Stability (collection to initiation of testing): After separation of cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 1 month
Reference Interval:
Effective May 16, 2011
 
 Males Females
0-3 days 5.17-14.60 mU/L 5.17-14.60 mU/L
4-30 days 0.43-16.10 mU/L 0.43-16.10 mU/L
1-24 months 0.62-8.05 mU/L 0.62-8.05 mU/L
2-6 years 0.54-4.53 mU/L 0.54-4.53 mU/L
7-11 years 0.66-4.14 mU/L 0.66-4.14 mU/L
12-19 years 0.53-3.59 mU/L 0.53-3.59 mU/L
20 years and older 0.30-4.00 mU/L 0.30-4.00 mU/L
1st trimester (10-13 weeks gestation)  0.03-3.40 mU/L
2nd trimester (14-20 weeks gestation)  0.19-4.06 mU/L

Note: If the Thyroid Stimulating Hormone is outside the reference interval, then Thyroxine, Free (Free T4) testing will be added. Additional charges apply.
CPT Code(s): 84443; if reflexed 84439
Cross References: Thyrotropin (Thyroid Stimulating Hormone), TSH (Thyroid Stimulating Hormone)