TSH : 899

Test Code
TSH3C or 899


Alias/See Also
Thyrotropin,Thyroid Stimulating Hormone


CPT Codes
84443

Instructions
Specimen collection after fluorescein dye angiography should be delayed for at least 3 days. For patients on hemodialysis, specimen collection should be delayed for 2 weeks.


Transport Container
Specimen:
1 mL serum
Minimum Volume: 0.7 mL


Transport Temperature
Room temperature.


Specimen Stability
Room temperature: 7 days; Refrigerated: 7 days; Frozen: 28 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Plasma


Methodology
Immunoassay

Setup Schedule
Sunday - Saturday


Report Available
1 day


Limitations
According to the assay manufacturer Siemens: "Samples containing fluorescein can produce falsely depressed values when tested with the Advia Centaur TSH3 Ultra assay."


Reference Range
Premature Infants (28-36 Weeks)    
  1st Week of Life 0.20-27.90 mIU/L  
Term Infants (>37 Weeks)    
  Serum or Cord Blood 1.00-39.00 mIU/L  
  1-2 Days 3.20-34.60 mIU/L  
  3-4 Days 0.70-15.40 mIU/L 
  5 Days-4 Weeks 1.70-9.10 mIU/L 
  1-11 Months  0.80-8.20 mIU/L  
  1-19 Years 0.50-4.30 mIU/L  
  ≥20 Years 0.40-4.50 mIU/L 
Pregnancy   
  First Trimester 0.26-2.66 mIU/L  
  Second Trimester 0.55-2.73 mIU/L 
  Third Trimester 0.43-2.91 mIU/L 
TSH levels decline rapidly during the first week of life in most children, but may remain transiently elevated in a few individuals despite normal free T4 levels. For proper interpretation of an abnormal TSH from a newborn thyroid screen, a Total T4 (test code 867) should be considered.


Clinical Significance
For differential diagnosis of primary, secondary, and tertiary hypothyroidism. Also useful in screening for hyperthyroidism. This assay allows adjustment of exogenous thyroxine dosage in hypothyroid patients and in patients on suppressive thyroxine therapy for thyroid neoplasia.


Performing Laboratory
med fusion



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.