Gestational Glucose Tolerance Diagnostic Test (Three-hour, ACOG Recommendations)

Casandra

Casandra Test Code LC46218Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 102004CPT Codes 82951, 82952

Gestational Glucose Tolerance Diagnostic Test (Three-hour, ACOG Recommendations)

Also known as: Glucose Tolerance, Gestational Diabetes (Fasting, One-hour, Two-hour, and Three-hour)

Clinical Use

Order Test

Use

Diagnose gestational diabetes

Special Instructions

Patients must adhere to a specific diet and fasting protocol before the test: an unrestricted diet of at least 150 grams of carbohydrates for three days prior, and fasting for at least 8 hours but no more than 14 hours before the test. Discontinuation of nonessential glucose-altering medications is advised three days before testing. Patients should remain seated and avoid smoking during the test.

Limitations

The test may not be suitable for patients with known diabetes mellitus or those under physiological stress such as surgery or infection. Accurate results require strict adherence to fasting and preparation protocols. Incorrect specimen labeling with collection time intervals can lead to test rejection.

Test Details

Methodology

Automated Analyzer (Clinical Chemistry)

Biomarkers

4 targets

Glucose - 1 hourGlucose - 2 hourGlucose - 3 hourGlucose - Fasting

LOINC Codes

Order Codes

50586-7

Result Codes

1558-6
1501-6
1514-9
1530-5

Result Turnaround Time

1 day

Specimen

Serum

Volume

1 mL serum each tube

Minimum Volume

0.5 mL serum each tube

Container

Gel-barrier tubes (4)

Collection Instructions

Draw fasting blood sugar before administering 100-gram glucose, then draw blood at one, two, and three hours. Separate serum from cells within 45 minutes of venipuncture. Label each tube with patient's name and collection time interval (i.e., fasting, one-hour, two-hour, and three-hour).