1-Hour Gestational Diabetes Test (O’Sullivan Testing)

1 Hour Gestational Diabetes Screen

Why am I Having This Test?

This test is being performed to screen for gestational diabetes, or elevated blood sugar levels during pregnancy. Having elevated blood sugar levels during pregnancy can affect your baby and delivery. Most pregnant women should have this test performed between 26-28 weeks. Some women have this test done more than once if they are considered to be high risk for having gestational diabetes or if the original test was performed prior to 24 weeks. Your physician will advise you as to what is recommended.

How is This Test Done?


You will be given a drink containing glucose from your physician. This is usually given to you around 24 weeks to be drank prior to your 28 week appointment. It is recommended you put the drink in the refrigerator; it seems to taste better cold. You will then drink the entire bottle within 5 minutes. You will then need to have your blood drawn 1 hour after completing the drink. It is recommended showing up at lab 15 minutes prior to the 1 hour time limit, just in case there is a wait – lab will not draw you if you are over the 1 hour limit and you will have to do the drink again.

What Do I Do On The Day of The Test


On the day of testing, avoid foods or snacks that are high in sugar, otherwise you should eat normally. Time your blood draw to complete the test prior to your physician appointment. Your blood needs to be drawn exactly 1 hour from completion of the glucola drink. Make sure you alert lab personnel that you are there for a timed diabetic test and the time you are due to be tested. Once your blood has been drawn, come to your regular scheduled physician appointment.

What Do The Test Results Mean

A normal or negative result means that you do not have gestational diabetes.
An abnormal or positive result means that you are at risk for gestational diabetes and an additional test, called a 3 hour glucose tolerance test, will need to be performed. You will be given specific instructions should you need to have this test done.

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Phone: 262-544-4411
Fax: 262-650-3856

Moreland OB-GYN Associates, S.C. now offers nine locations to serve your needs. Visit us in Waukesha,
Mukwonago, Sussex, Brookfield, Hartland, Delafield, Oconomowoc Hostpital, Oconomowoc Physician Center & Watertown.

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