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Test Code GEST GLU Diabetes, Gestational Screen, Blood or Serum

Performing Laboratory

ChristianaCare

Methodology

Glucose Oxidase/Hydrogen Peroxide (Trinder)

The American Diabetes Association recommends the screening of at risk pregnant women between the 24th and 28th weeks of gestation. Screening should be performed on women meeting the following criteria:
1. ≥25 Years of age
2. <25 Years of age and obese (≥20% over desired body weight)
3. Family history of diabetes in first-degree relative
4. Ethnic racial groups:  Hispanic-American, Native American, Asian-American, African-American, and Pacific Islander
Pregnant women meeting none of these criteria are at a lower risk for the development of glucose intolerance during pregnancy, and it is likely not cost-effective to screen such individuals.

Specimen Requirements

Submit only 1 of the following specimens:

 

Blood

Container/Tube:  Gray top (potassium oxalate/sodium fluoride) tube
Specimen:  Full tube

Collection Instructions:  1. Patient should remain seated comfortably during the test. No undue exercise or smoking.

2. Draw specimen at 24 to 28 weeks of pregnancy.

3. Administer 2/3 of the 10 ounce bottle (296 mL), or 6.7 ounces (197 mL) of Trutol 75g Glucose Tolerance Test Solution, or 50 g of glucose. Patient should drink this within 5 minutes.

Note:  The solutions are considered more palatable when served over crushed ice.

4. Draw blood 1 hour after ingestion of glucose beverage.

5. Gently invert tube to mix blood and anticoagulant.

6. Forward promptly.

Note:  1. Indicate blood on request form.

2. Label tube with patient’s full name and 1 additional unique patient identifier such as date of birth, medical record number, emergency ID number, date and time of draw, collector’s initials, type of specimen, and as blood.

 

Serum

Container/Tube:  3.5-mL red-top (gel) tube
Specimen:  Full tube
Collection Instructions:  1. Patient should remain seated comfortably during the test. No undue exercise or smoking.

2. Draw specimen at 24 to 28 weeks of pregnancy.

3. Administer 2/3 of the 10 ounce bottle (296 mL), or 6.7 ounces (197 mL) of Trutol 75g Glucose Tolerance Test Solution, or 50 g of glucose. Patient should drink this within 5 minutes.

Note:  The solutions are considered more palatable when served over crushed ice.

4. Draw blood 1 hour after ingestion of glucose beverage.

5. Gently invert tube to mix blood and clotting agent.

6. Forward promptly.

7. If at outpatient site, allow blood to clot and centrifuge before sending to the lab.

Note:  1. Indicate serum on request form.

2. Label tube with patient’s full name and 1 additional unique patient identifier such as date of birth, medical record number, emergency ID number, date and time of draw, collector’s initials, type of specimen, and as serum.

Reference Values

Normal:  glucose <140 mg/dL

Abnormal screens should be followed up with a 100 g, 3 hour glucose tolerance test to confirm the finding.

Day(s) Test Set Up

Monday through Friday

Routine Turnaround Time:  not available

STAT Turnaround Time:  not available