3 HOUR GESTATIONAL ORAL GLUCOSE TOLERANCE TEST (OGTT)

Message

A total of 4 specimens will be drawn.

Draw fasting specimen
Administer 100g oral glucose (Glucola) or dose specified by physician
Draw specimen 1 hour after consumption of oral glucose (Glucola)
Draw specimen 2 hours after consumption of oral glucose (Glucola)
Draw specimen 3 hours after consumption of oral glucose (Glucola)

Test Code

3GGTT

Alias/See Also

GTT

CPT Codes
82951, 82952

Includes

Baseline (glucose) fasting
1 hour glucose (post 100g dose)
2 hour glucose (post 100g dose)
3 hour glucose (post 100g dose)

Preferred Specimen

1 Gold tube (gel separator)

Minimum Volume

0.5 mL

Other Acceptable Specimens

1 Lavender tube (EDTA) or
1 Green tube (Lithium Heparin) or
1 Gray tube (Sodium Fluoride)

Instructions

Separate serum or plasma from red cells rapidly to minimize the loss of glucose through glycolysis. Refrigerate until tested.

Transport Temperature

Refrigerate

Specimen Stability

2-8°C up to 3 days
15-30°C up to 24 hours (plasma)
15-30°C up to 8 hours (serum)

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

Hemolyzed

Methodology
Hexokinase

Setup Schedule

M. Tu, W, Th, F, Sa, Su

Report Available

Within 24 hours of receipt at the performing laboratory.

Reference Range

Test	Result mg/dL
Baseline (Fasting)	70-94
1 Hour Glucose	70-179
2 Hour Glucose	70-154
3 Hour Glucose	70-139

Clinical Significance

Establish the diagnosis of diabetes mellitus in the pregnant patient. This test is the follow-up test in the two-step approach recommended by the Anmerican College of Obstetrics and Gynocology (ACOG).

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NCHB1 (Chemistry, Beckman AU)

Last Updated: June 8, 2023

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.