Looking for Primary Care services? Schedule online with an Iowa Clinic provider.

Skip to Main Content
Obstetrics & Gynecology Pregnancy & Delivery

Obstetrics & Gynecology

  Schedule Lab Draw

Pregnancy Glucose Tolerance Test

What is a pregnancy glucose screening?

Glucose testing during pregnancy is typically conducted around 28 weeks to test for gestational diabetes. Gestational diabetes can only occur during pregnancy. It is a result of high blood sugar levels. Your provider will discuss the details of this test in your 20 or 24 week appointment.

Preparing for the glucose screening

You do NOT need to fast prior to the gestational diabetes test. Be sure to discuss all medications and supplements with your provider ahead of time to reassure that no adjustments are needed.

Taking the gestational diabetes test

Day of instructions:

  • Plan on 1.5 hours for the visit (includes glucose testing and scheduled OB appointment)
  • Reserve a spot in line at the lab 20 minutes ahead of your OB appointment time (no later than 3:15pm MTh and no later than 1:45pm on Fridays).
    • When reserving a spot at the lab, select ‘Adult Lab Draw’ from the drop down to view dates and times available.
  • Arrive at your lab appointment time and go directly to the lab. Use the Kiosk upon arrival, clicking ‘Yes, I saved my place in line’ to check in for your reservation.
  • After checking in, go to the lab front desk to receive the glucola for your pregnancy glucose screening.
    • Glucola must be consumed in 5 minutes or less. This can be done in the lab waiting area.
    • After finishing the glucola, NO EATING OR DRINKING IS PERMITTED.
    • Wait 1 HOUR before having your blood drawn.
  • Once you finish the glucola, check-in and attend your OB appointment.
  • Following your OB appointment and the 1-hour wait time after finishing your glucola, return to the lab for your blood draw.
    • No reservation necessary this time. Just check back in with the lab front desk.

After the pregnancy glucose screening

If your 1-hour glucose test results comes back normal (blood sugar equal or less than 140mg/dL (7.8 mmol/L), no additional appointments are needed.

If your results come back higher than 140mg/dL you will likely be asked to come back for a 3-hour glucose test.

3-hour glucose test

To prepare for the 3-hour glucose test you can eat and drink as normal up to 12 hours before the test. You will need to fast 12 hours prior to the test. It is easiest to fast overnight and complete the test in the morning. Once the test begins, you may only drink plain water. Be sure to check with your provider on lab appointment details (when to arrive).

Once you arrive for your test, you will have a fasting blood sugar drawn. After, you will receive your glucola which must be consumed in five minutes or less. You will then have your blood drawn at hour 1, 2 and 3 for a total of 4 blood draws that day. Be sure to bring something to occupy your time as you will need to stay around the lab and clinic for the duration of those three hours. It’s also advised to bring something to eat afterward as you will likely be hungry and possibly nauseated from the test.

  Schedule Lab Draw

Back to top