Glucose tolerance test
OGTT · oral glucose tolerance test · glucose challenge test · gestational diabetes test
This test checks how your body handles sugar. Blood is taken while fasting, and again 2 hours after you drink a glucose solution.
If diabetes or prediabetes is suspected, and usually for all pregnant women at 24 to 28 weeks.
⏱ Duration: about 2 to 2 and a half hours at the clinic
Be sure to tell your doctor
How to prepare
- Food. No food for 10 to 14 hours before the test. Water is fine.
- 3 days before. Eat as usual. Do not diet, or the result will be wrong.
- In the morning. Do not smoke or chew gum. Bring a book. You will wait a long time.
What to bring
- Your referral
- Water and a snack for after the test
How it goes
- First, blood is taken while you are fasting
- You drink a glass of sweet glucose solution within 5 minutes
- For two hours you sit quietly at the clinic: no eating, no smoking, no brisk walking
- After 2 hours, blood is taken again
What you'll feel
- The drink is very sweet and may make you a little sick. Take small sips
- Sometimes you feel weak toward the end of the wait
Afterwards
- You can eat after the second blood draw
- Results usually come in 1 to 2 days. Your doctor will explain them
Contact a doctor straight away if
- Strong weakness, sweating, or shaking: tell the nurse right away
Common questions
Can I go for a walk during the test?
Better not. Moving changes your blood sugar. Stay seated at the clinic.
What if I throw up after the glucose drink?
Tell the nurse. The test will most likely be moved to another day.