Glucose Tolerance Test

Blood Sugar Testing During Pregnancy

Beth Israel Deaconess Medical Center (BIDMC) provides comprehensive pregnancy care for expecting moms and their babies. The The one-hour Glucose Loading Test (GLT) helps measure how your body is using sugar during your pregnancy. This test is important because pregnancy hormones can cause the level of sugar in your body to be too high. High levels of sugar can increase risks for you or your baby if not managed appropriately.

The GLT is a screening test for gestational diabetes (diabetes during pregnancy). If your GLT comes back normal, then you do not have gestational diabetes. If your GLT comes back higher than normal, your doctor will have you come back to the office for a follow-up test called a three-hour Glucose Tolerance Test (GTT). If your GTT is also elevated, then this means you have gestational diabetes. Your prenatal care team can help you safely manage gestational diabetes. Your doctor will talk with you more about this condition once the test results are back.

Preparing for the Glucose Loading Test

Do not eat or drink anything after midnight the night before your test. Prior to this fasting period, don’t change your diet at all, eating as you normally would.

Preparing for the Glucose Monitoring Test

Do not eat or drink anything after midnight the night before your test. Prior to this fasting period, don’t change your diet at all, eating as you normally would. Your care team will help you schedule your GTT on a morning that works for you.

What to Expect

Here are some tips on how to be prepared for your GTT:

• Plan to be at the office for four hours for this test.
• Report to lab in the OBGYN office on Shapiro 8 on the BIDMC East Campus at the time your prenatal team told you.
• You’ll have blood drawn when you arrive.
• You’ll drink a sweet liquid (Glucola), all of it within five minutes.
• Tell the phlebotomist what time you finished drinking the Glucola.
• You’ll have more blood drawn at one hour, two hours, and at three hours after you drink the Glucola.
• You may drink only water during this test. You may eat and drink as usual once we complete the final blood test.

Getting Your Glucose Test Results

Your healthcare provider will have the results the day after the test. If the GTT shows that you have gestational diabetes, you can count on the experts at BIDMC for comprehensive care.