Glucose Tolerance Test (1 Hr/50g) Gestational - Non -Fasting
Additional Codes
Epic# -
LAB5712
Cerner name(s):
- GTT 50 gram 1hr gestational screen or Glucose Tolerance testing 50 gram 1hr gestational screen
Performing Lab(s)
Memorial-Belleville & Memorial-Shiloh
Specimen Requirement (s)
Specimen Type: plasma (preferred) or serum
Container/Tube: mint green LiHep tube, SST (gold or marble), plain red top, lavender (EDTA) tube
Specimen Volume: full tube
Specimen Minimum Volume: 1 mL of plasma
Collection Instructions:
- Give patient 50 g glucose tolerance beverage (or acceptable substitute as determined by lab or physician)
- Draw specimen at 1 hour post consumption of beverage.
Unacceptable Conditions
Avoid hemolysis.
Day(s)/Shift(s) Test Set Up and Turnaround Time
Sunday through Saturday
Hours: 24 hours
Turnaround Time:
STAT: No
Routine: less than 8 hours from receipt.
Transport and Stability
Transport temperature: Ambient to lab
Reference Values
Non-Fasting 1 Hour (1H/50g)
Reference Values |
Critical Low |
Critical High |
≤ 140 mg/dL |
≤ 54 mg/dL |
≥ 450 mg/dL |
CPT/LOINC Codes
82950
Interpretive Data
Interpretive Data
Used for suspected gestational diabetes. The screeningtest uses 50 grams of glucose with sample obtained 1 hr later.
Normal range: < 140 mg/dL.
A glucose value of >140 mg/dL generally indicates the need for a full diagnostic tolerance test.
Reference Interval Info:
Diabetes Care 2005, Vol 28. Supplement 1,S37-S42. Report of the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus. Diabetes Care 2020; 43(Supplement 1):S14-31.