A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Glucose, Gestational Screen (50g) 140 Cutoff
Test Code19833
CPT Codes
82950
Preferred Specimen
1 mL timed plasma collected in fluoride/oxalate (gray-top) tube
Minimum Volume
0.5 mL
Other Acceptable Specimens
Timed full tube of whole blood collected in: fluoride/oxalate (gray-top) tube • Timed plasma collected in: sodium or lithium heparin (green-top) tube • Timed serum collected in: serum separator tube (SST®)
Instructions
The test should be performed between weeks 24 and 28 of gestation. The patient is given a 50 gram dose of glucose and a single blood specimen is obtained one hour later. Fasting is not required. Ship at room temperature.
Serum specimens are also accepted. Remove plasma and serum from cells immediately.
Whole blood: ship tubes refrigerated (cold packs)
Serum specimens are also accepted. Remove plasma and serum from cells immediately.
Whole blood: ship tubes refrigerated (cold packs)
Transport Temperature
Serum and plasma: Room temperature
Whole blood: Refrigerated (cold packs)
Whole blood: Refrigerated (cold packs)
Specimen Stability
Sodium fluoride plasma (preferred)
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Serum
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
Whole blood
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable
Heparinized plasma
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Serum
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
Whole blood
Room temperature: 24 hours
Refrigerated: 72 hours
Frozen: Unacceptable
Heparinized plasma
Room temperature: 48 hours
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Unspun serum separator tube • Red-top tube • Non-plasma separator green-top tubes • Anticoagulants other than lithium heparin • Sodium heparin or fluoride/oxalate
Methodology
Spectrophotometry (SP)
Setup Schedule
Set up: Daily; Report available: Next day
Limitations
Glucose levels may be depressed if sample is left on clot for an excessive length of time.
Reference Range
<140 mg/dL
Clinical Significance
A value of 140 mg/dL or greater indicates the need for a full diagnostic, gestational glucose tolerance performed in the fasting state to determine if the patient has gestational diabetes.
Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153