TSH, Pregnancy

Test Code
90896


CPT Codes
84443

Preferred Specimen
1 mL serum


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

Minimum Volume
0.7 mL


Transport Container
Plastic screw-cap vial


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 (IA)

Setup Schedule
Set up: Daily; Report available: 1 day


Reference Range
First Trimester 0.26-2.66 mIU/L
Second Trimester 0.55-2.73 mIU/L
Third Trimester 0.43-2.91 mIU/L
Results are flagged based on the first trimester assay-specific reference interval. For later stages of pregnancy, interpret results based on the trimester-specific reference intervals provided.


Clinical Significance
TSH levels are lower during pregnancy, especially during the 1st trimester. Based on recent clinical studies which have shown that even mildly elevated TSH during pregnancy is associated with adverse pregnancy outcomes, the American Thyroid Association has released clinical guidelines which recommend the use of assay-specific and trimester-specific reference intervals.


Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153




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.