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Specimen Collection Manual and Test Catalog

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50-G GESTATIONAL GLUCOSE, 1 HOUR

Geisinger Epic Procedure Code:  LAB1493    Geisinger Epic ID:  6690

SPECIMEN COLLECTION
Specimen type: 

Plasma


Preferred collection container: 
Specimen required: 

1 mL aliquot of plasma; minimum 0.2 mL


Special notes: 

Place specimen on ice, or centrifuge and separate plasma from cells.


Patient preparation: 

Specimen collected 1 hour after 50-gram glucose challenge. Fasting not required.



SPECIMEN PROCESSING
Processing instructions: 

Centrifuge to separate plasma within 2 hours of collection.


Transport temperature: 

Refrigerated (preferred). Room temperature also acceptable.


Specimen stability: 

3 days (spun and unspun).


Rejection criteria: 

Stability limits exceeded.



TEST DETAILS
Reference interval: 

70-129 mg/dL


Critical values/courtesy alerts: 
Glucose below 45, above 500 mg/dL
Additional information: 

Test routinely performed during pregnancy.


CPT code(s):  82950
Note: The billing party has sole responsibility for CPT coding.  Any questions regarding coding should be directed to the payer being billed.
The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only.

Test includes: 

Gestational glucose test 1 hour post 50 gm glucose challenge.


Methodology: 
Spectrophotometric (Colorimetric)
Synonyms: 

Blood sugar, GLUG, GTT


Clinical significance: 

An elevated value indicates the need for a full diagnostics gestational tolerance performed in the fasting state to determine if the patient has gestational diabetes.


Doctoral Director(s): 
Hoi-Ying Elsie Yu, PhD, DABCC, FADLM
Sheng-Ying (Margaret) Lo, PhD, DABCC
Review Date:  12/27/2024

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