Test Code LAB2811 Gestational Glucose Challenge (Obstetrical Patients Only)
Additional Codes
CPT Code: 82950
Patient Preparation Before Testing
1. Patient does not need to be fasting prior to testing.
2. Patient should be instructed to refrain from exercise, smoking, and drinking coffee just before and during test.
3. Patient should be instructed not to eat or drink anything for the hour after the glucose solution has been administered.
Administering Glucose Solution
1. Give the patient a 50 g glucose solution. Instruct the patient to drink the whole amount within several minutes.
2. Start timing when patient begins to drink the glucose solution.
3. Have patient remain quiet for duration of test.
4. Draw blood specimen at precisely 1-hour post glucose administration.
Specimen Collection
Precisely 1-hour after the solution was administered, collect a green-top (lithium heparin plasma) tube. Serum Gold-top, Plain Red, and Tiger-top SST tubes are also acceptable, but are not preferred.
Centrifuge the sample and send 2 mL of plasma or serum separated from contact with the cells. Tubes with gel barriers do not need to be aliquoted after centrifugation. Serum from Plain Red tubes must be aliquoted immediately after centrifugation.
Samples should be refrigerated at 2-8° Celsius if testing will not be performed within 2 hours of draw. Refrigerated samples are stable for 48 hours.
Performing Laboratory
TidalHealth Peninsula Regional - Core Laboratory: Chemistry
Reference Values
Reference Range
60-139 mg/dL
Critical Action Values
<50 mg/dL or >500 mg/dL