The glucose tolerance test is a lab test to check how your body moves sugar from the blood into tissues like muscle and fat. The test is often used to diagnose diabetes. Tests to screen for diabetes during pregnancy are similar, but are done differently.

SPECIMEN: 2 mL (1 mL min.) plasma from 1 Grey Top (Sodium Fluoride) tube for each timed specimen. Draw baseline fasting specimen. Dissolve 110 g of glucose monohydrate (equivalent to 100 g anhydrous glucose) in 300 mL water. Administer orally over a period of 5 minutes. Draw additional specimens at 1.0, 2.0 & 3.0 hrs. Note time drawn on each container label and test request form.
STABILITY: Room: 6 hrs; Refrigerated: 72 hours; Frozen: 1 week
REPORT: Daily
INSTRUCTIONS: Overnight fasting is mandatory.
USAGE: This is the recommended test for pregnant patients. If results are normal in a clinically suspected case of Gestational Diabetes mellitus, a repeat test in third trimester is recommended.