Gestational Diabetes Screen (ACOG Recommendations)
Also known as: Glucose Tolerance, Gestational Diabetes (One-hour)
Use
Screening test for gestational diabetes
Special Instructions
Not provided.
Limitations
The screening test is not definitive for diagnosing diabetes mellitus and should not be used in patients with a known history of diabetes mellitus. The test requires adherence to specific collection instructions for accurate results. A glucose threshold of >139 mg/dL identifies approximately 80% of women with GDM, but sensitivity increases to 90% with a threshold >129 mg/dL. Results must be interpreted in the context of clinical history and in conjunction with confirmatory tests.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
LOINC Codes
- 1504-0 - Glucose 1h p 50 g Glc PO SerPl-mCnc
- 1504-0 - Glucose 1h p 50 g Glc PO SerPl-mCnc
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL serum or plasma each tube
Minimum Volume
0.5 mL serum or plasma each tube
Container
Gel-barrier tube or gray-top (sodium fluoride/potassium oxalate plasma) tube
Collection Instructions
Draw one-hour specimen after a 50-gram glucose challenge. Submit 1 mL serum or plasma for one-hour specimen. Separate serum or plasma from cells within 45 minutes of venipuncture. Gray-top tubes may be submitted without centrifugation.
Patient Preparation
None; glucose challenge is administered without regard to time of day or time of last meal.
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Frozen gray-top tube (frozen plasma from gray-top is acceptable); stressed patient (surgery, infection, corticosteroids) should not have GTT; specimen not labeled with collection time intervals (i.e., one hour)
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
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