| Ordering Code | 6644 |
|---|---|
| Test Name | 2 Hr Glucose Tolerance, Pregnancy |
| Alias | Glucose Tolerance Test - 2 Hr, Pregnancy GTT, 2 Hr, Pregnancy |
| Preferred Specimen | Serum Note: If specimen cannot be properly processed within 1 hour of collection, collect blood in Oxalate/Fluoride (Gray). |
| Preferred Container | SST (Gold) |
| Other Specimen/Container | Plasma in Sodium Fluoride-Potassium Oxalate (Gray), Serum in Plain (Red), Plasma in Lithium Heparin (Green-PST), Plasma in Lithium Heparin (Dark Green-PP No Gel) |
| Optimum Volume | 1 mL |
| Collection Instructions | Patient must be fasting 10-12 hours, minimum 8 hours Draw fasting sample. Administer a 75 gram glucose load Patient should remain inactive and receive nothing by mouth except for small amounts of water or ice. Collect blood specimen 1 hour and 2 hour post glucose load. |
| Handling Instructions | If specimen cannot be properly processed within 1 hour of collection, collect blood in Sodium Fluoride-Potassium Oxalate (Gray) All specimen types must be centrifuged within 2 hours of collection. If no gel separation present in tube and testing is delayed, plasma/serum is aliquoted from cells within 2 hours of collection. |
| Transport Requirements | Oahu: Refrigerated Airline: Refrigerated |
| Specimen Stability | Ambient: 8 Hours Refrigerated: 3 Days Frozen: 3 Months (Aliquot) Frozen samples should be thawed only once Unprocessed Sodium Fluoride-Potassium Oxalate (Gray) blood is stable 3 days ambient. |
| Rejection Criteria | Specimen older than stability limits, Grossly Hemolyzed, Insufficient quantity, Unprocessed within allowable time limit |
| Avail. Stat | NO |
| Analytic Time | 1 Day |
| Methodology | Hexokinase-UV/NAD |
Reference range(s)
The reference ranges listed below are valid on this date of August 31, 2025.
| Component | Age | Male Norm | Male Critical Low | Male Critical High | Female Norm | Female Critical High | Female Critical Low | Units | Add'l info |
|---|---|---|---|---|---|---|---|---|---|
| Fasting | ALL | YES | |||||||
| Glucola Dose: | ALL | 75 | grams | ||||||
| Reaction To Glucola | ALL | See report. | |||||||
| Special Instructions | ALL | See report. | |||||||
| Glucose, Fasting | ALL | 70-91 | >= 400 | <= 50 | mg/dL | ||||
| Glucose, 1 Hr | ALL | 70-179 | >= 400 | <= 50 | mg/dL | ||||
| Glucose, 2 Hr | ALL | 70-152 | >= 400 | <= 50 | mg/dL |
