The O’Sullivan test measures pregnant women’s body’s reaction to glucose (sugar). The test is administered between the 26-28 week mark during the pregnancy and is done to screen for gestational diabetes.
Gestational diabetes is a condition when women without diabetes develop high blood sugar levels while they are pregnant.
After going through the test, which is further explained below, you will know if your levels are below normal, normal, or above normal. If your levels are abnormal, you will need to schedule additional tests to confirm your diagnosis.
The values that are used to determine gestational diabetes were first detected by O’Sullivan and Mahan in 1964 during a study designed to be able to recognize the risk of developing type 2 diabetes. Later the test was informally named after O’Sullivan.
Video Transcription:
Hi, I’m Nicole, I’m a nurse here at Moreland OB-GYN and I‘m here to you about our two glucose tests that we do during pregnancy. These tests measure the pregnant women’s reaction to glucose and screen for gestational diabetes which is a condition when a woman that does not have diabetes ends up with elevated high glucose levels. Having elevated blood sugar during pregnancy can affect your baby and your delivery. Advanced maternal age, your activity level, being overweight, or having a family member with diabetes all are factors that can contribute to gestational diabetes. First, I will explain the 1-hour glucose test, otherwise known as O’Sullivan Testing. You will be given a drink, like this, typically at your 24-week prenatal visit. You will be expected to drink the liquid prior to your next visit between 26 and 28 weeks of pregnancy. You need to drink this within 5 minutes, and then you will have to have your blood drawn one hour from that time. What does the drink taste like? It’s very sweet so we recommend drinking it straight from the fridge so it’s nice and cold to help control that sweetness. It is recommended to avoid foods or snacks that are high in sugar prior to the test. A normal or negative test result means you do not have gestational diabetes. However, an abnormal or positive test result means you are at risk for having gestational diabetes and we will need you to do the three-hour glucose test. So how does the three-hour test work? There are multiple blood draws for the three-hour glucose test, the first after fasting for 8-12 hours. Then you will be given a similar glucose liquid to drink and blood samples will be taken at 1, 2, and 3 hours after completing that drink. Because activity can interfere with the results, you will need to stay in the lab during the duration of the test, so we recommend bringing something to read, a project to work on, something to watch while you are waiting. You may drink plain water during the test however no food can be consumed at the time. Bring a snack for after cause you may be quite hungry. Based on the results of this test and other criteria that your doctor uses, you will be given a diagnosis. If you’re positive after this test, your physician will provide you information and other resources on how to manage your gestational diabetes. We hope this video gave you an overview of the testing performed to check for gestational diabetes. We have additional information on our website – Moreland o-b-g-n dot com, and if you still want more information, please ask your physician at your next visit. As always, it's our job here at Moreland to lead women to better health.
You will be given a drink containing glucose from your physician. This is usually given to you when you are around 24 weeks to drink prior to your 28-week appointment. It is recommended you put the drink in the refrigerator; it seems to taste better cold.
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.
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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.
