Glucose, Fasting and Gestational, 135 Cutoff
Also known as: Glucose, Gestational Screen, Gestational, Glucose
Use
This test evaluates both fasting glucose levels and blood glucose response one hour after a 50 g glucose challenge, using a 135 mg/dL cutoff as a preliminary screen for gestational diabetes. Results above the cutoff suggest increased risk and typically prompt a follow-up OGTT (oral glucose tolerance test).
Special Instructions
Performed typically between weeks 24 and 28 of gestation. Requires two blood draws: a fasting sample, then a post-load sample one hour after ingestion. Use gray-top fluoride/oxalate tubes for plasma; label specimen draw times.
Limitations
A result above the 135 mg/dL cutoff indicates risk but is not diagnostic; a follow-up diagnostic OGTT is recommended. Interpretation may vary depending on clinical guidelines and gestational age.
Methodology
Automated Analyzer (Clinical Chemistry)
Biomarkers
Result Turnaround Time
1-2 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.5 mL
Container
Gray‑top fluoride/oxalate tube (preferred). Acceptable: lithium or sodium heparin (green‑top) plasma or SST serum.
Collection Instructions
Collect first fasting plasma specimen, then 50 g glucose load, then second specimen 1 hour later; label draw times.
Patient Preparation
Fasting required (no food or beverage except water for at least 8 hours before first draw).
Storage Instructions
Ship plasma tubes at room temperature.