When do i take my glucose test

Pregnant women can develop a condition known as Gestational Diabetes (diabetes brought on by pregnancy) which can pose a risk to both mother and baby. A glucose tolerance test is a common type of testing for potential gestational diabetes.

There are several tests intended to identify gestational diabetes in pregnant women. The first, called the Glucose Challenge Screening, is a preliminary screening test performed between 26-28 weeks. If a woman tests positive during this screening test, the second test, called the Glucose Tolerance Test, may be performed. This test will diagnose whether diabetes exists or not by indicating whether or not the body is using glucose (a type of sugar) effectively.
The Glucose Challenge Screening is now considered to be a standard test performed during the early part of the third trimester of pregnancy.

What is the Glucose Challenge Screening Test?

No preparation is required prior to the test. During the test, the mother is asked to drink a sweet liquid (glucose) and then will have blood drawn one hour from having the drink, as blood glucose levels normally peak within one hour. No fasting is required prior to this test.

The test evaluates how your body processes sugar. A high level in your blood may indicate your body is not processing sugar effectively (positive test). If the results of this screen are positive, the woman may have the Glucose Tolerance Test performed. It is important to note that not all women who test positive for the Glucose Challenge Screening test are found to have diabetes upon further diagnosis.

What is the Glucose Tolerance Test?

Prior to the taking the glucose tolerance test, your doctor will ask you to make sure and eat at least 150 mg of carbohydrates (about what you will get from a slice or two of bread) for three days prior to the time you will be asked to fast. You will not be permitted to eat or drink anything but sips of water for 14 hours prior to the test, so it is best to schedule the test for first thing in the morning.

Additionally, you should plan to have someone drive you to and from the test since your energy levels may be low and there is a slight possibility you may feel light-headed.

3-Hour Glucose Test

When you arrive, the technician will draw blood to measure your baseline “fasting blood glucose level”. You will be asked to drink a larger volume (or more concentrated solution) of the glucose drink than was used in the initial Glucose Challenge Screening test. Your blood will be drawn and tested every hour for the next three hours.

The following are the values that the American Diabetes Association considers to be abnormal during the Glucose Tolerance Test:

What if my Glucose Tolerance Test Results are Abnormal?

If only one of your readings comes back abnormal, your doctor may suggest some changes to your diet and/or test you again later in the pregnancy. If two or more of your readings come back abnormal, you’ll be diagnosed with Gestational Diabetes and your doctor or midwife will talk to you about a treatment plan. Treating diabetes during pregnancy is extremely important to protect the health of both mother and baby.

Want to Know More?

• Pregnancy Nutrition
• Pregnancy Exercise Guidelines

Compiled using information from the following sources:

1. American Diabetes Association

https://www.diabetes.org

2. Emedicine

https://www.emedicine.com

3. National Institute of Diabetes and Digestive and Kidney Diseases

https://www.niddk.nih.gov

This test is done to evaluate how your body is processing sugar and to determine if you have developed Gestational Diabetes (Diabetes of Pregnancy).

The test requires a total of four blood draws. The first is done fasting (after you have had nothing to eat or drink for at least 8-12 hours prior—except water).

Then you will be given a glucose liquid to drink that has a specific amount of sugar in it. Blood samples will be taken one, two, and three hours after you have completed this drink.

In preparation for this test:

• You should eat your normal diet prior to the day of testing.
• Do not eat, drink, smoke, or exercise for at least 8-12 hours before your first blood sample is taken. You may drink plain water but no other beverages.
• This test may take up to four hours to complete. Activity can interfere with the results so you will need to remain in the lab for the duration of the test.
• Consider bringing something to read or a project to work on while waiting.
• You may drink water so feel free to bring your own cup or water bottle.
• Once the test is completed, you may resume normal eating and drinking. You may be hungry once the test is finished, so you may want to bring along a light snack to eat before leaving or driving home.

Gestational Diabetes is typically diagnosed when two or more of the results are elevated. Your doctor may also use other criteria to make the diagnosis.

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.

How far in advance should I prepare for a glucose test?

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Does the glucose test have to be done in the morning?

What is the best time to check your blood sugar after eating?