Glucose Tolerance, Gestational Standard Fasting, 1 Hour, 2 Hour and 3 Hour (100g)


Abbrev Code:GTTGF   
Order Code:LAB770Order Name:Gestational Glucose Tolerance 3 Hour
Order Instructions:Order test panel; after collection of each specimen, the subsequent specimen will be generated in the patient's chart and can be brought into the collection activity at that time interval.
Synonyms:GTT; GTTG
Methodology:Bichromatic endpoint, glucose oxide
St Johns/St Joseph/Woodwinds: Hexokinase
CPT Codes: 82951 x1, 82952 x1
Test Includes:Fasting: GTTGF, LAB770, PLAB770; 1 Hour: GTTG1, LAB771, PLAB771; 2 Hour: GTTG2, GTTG75, LAB772, PLAB772; 3 Hour: GTTG3, LAB773, PLAB773. Standard dose is 100 g glucose during pregnancy.
Turnaround Time:Performed Mon-Fri, 0700-1700; turnaround time is 2 hours from the time the last specimen was collected.
Special Instructions:PCU/Clinic can obtain glucose solution from the pharmacy.


Collection Instructions

Specimen:Blood
Optimal Volume:2.5 mL
Minimum\Peds Volume:0.6 mL
Container:Green (lithium heparin, gel), St Johns/St Joseph/Woodwinds - Gray Na Fluoride)
Alternate Containers: Green (lithium heparin, no gel), Red (no gel), Red or gold (gel), St Johns/St Joseph/Woodwinds-Green (lithium heparin, no gel), St Johns/St Joseph/Woodwinds - Red (no gel), St Johns/St Joseph/Woodwinds - Purple (EDTA)
Collection Instructions:Glucose Tolerance Protocol  
  • Patient must plan to stay in the immediate area and remain quiet.
  • Measure fasting glucose level before glucose solution is administered. No caloric intake is required. Coffee, diet soda or gum are not allowed during fasting period. A fasting glucose greater than 126 mg/dL is reported to the physician before continuing the test,
  • Administer oral glucose solution and begin timing as patient finishes the glucose solution. Patient should finish drinking the solution within 10 minutes. Alternative dose is 75 grams glucose during pregnancy.
  • Collect specimens at 1 and 2 hours from the time the patient fnishes the glucose solution. Label each specimen with collection time, patient name and identification number.
  • For glucose tolerance blood specimens collected in hospital, deliver to laboratory individually as collected.
Patient Preparation:Please do not eat 10-12 hours before your appointment if you are coming in fasting for labs on lipids, cholesterol, or glucose (sugar). Water, hot tea and black coffee (with nothing added) is okay. Do not drink other fluids, diet soda or chew gum.
If you have concerns about taking your medications, please send a message by clicking on Secure Messaging, Message Your Care Team.  
Contraindications:If patient becomes ill or vomits, test must be discontinued.


Processing and Shipping

Specimen Processing:Centrifuge and aliquot 1.25 mL, 0.2 mL minimum. Store in refrigerator.
Shipping Instructions:Ship at refrigerated temperature.
Stability:Once separated from cells, Room temperature - 8 hours; refrigerated - 72 hours.
Test Performed at or Referral Lab Chemistry  (M Health Maple Grove Clinic, Range, UMMC-East Bank, Oxboro Bloom, Lakes, Ridges, Northland, Southdale, UMMC/UMMCH-West Bank, Clinics, M Health Clinic and Surgery Center, Grand Itasca, St. Joseph's, St. John's, Woodwinds)


Interpretive

Critical Range:Glucose Tolerance Reference Ranges
Reference Range:Glucose Tolerance Reference Ranges


Click HERE to Report test errors or omissions.
*If no email program is associated with this computer, please contact:
systemlabguide@fairview.org for TestID: 1183"