How It Is Done
- A blood sample is taken when you arrive for the test. This is your fasting blood glucose value. It will be compared to other glucose values in your blood.
- You will drink a small cup of very sweet liquid that contains 75 or 100 grams of glucose.
- You will have more blood tests over 1 to 3 hours.
- Since activity can affect test results, you will be asked to sit quietly during the entire test. Do not eat during the test. You may drink water during this time.
Glucose Tolerance Tests: What Exactly Do They Involve
Oral glucose tolerance tests are used to measure how well the body can process a larger amount of sugar. If the blood sugar measured in the test is above a certain level, this could be a sign that sugar is not being absorbed enough by the bodys cells. Diabetes or gestational diabetes might be at the root of this problem.
In gestational diabetes, blood sugar levels are often higher due to changes in the metabolism during pregnancy but they usually come back down again after the child is born.
What Is The Glucose Tolerance Test Like Do I Have To Fast
Fast overnight: Typically you’re instructed to eat a late meal the night before the test and then to eat or drink nothing after that, except for sips of water. The fasting period is usually 8 to 14 hours before the test, so you’ll want to schedule the test for first thing in the morning.
Here’s what to expect at the lab:
- First blood draw: When you arrive for the test, a blood sample is taken to measure your fasting blood glucose level.
- An even sweeter drink: Next, you’ll drink either a more concentrated dose or a larger volume of glucose solution.
- Three more blood draws: Brace yourself for three more arm pricks, as your blood is tested every hour for the next three hours. The lab tech should alternate arms each time your blood is drawn.
Some tips to make your test more comfortable:
- Have someone drive you to and from the test in case you feel lightheaded or are low on energy due to fasting.
- Bring something to distract you, because you have to stay nearby when your blood is not being drawn.
- Bring something to eat right after the final blood sample is taken, because you’ll probably be starving.
Results: After the test, if one of the readings is abnormal, you may have to take another test later in your pregnancy. Or your provider may ask you to make some changes in your diet and exercise routine. See “What is the treatment for gestational diabetes?” below.
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Can I Eat And Drink Before Having A Blood Test
It depends on the type of blood test you’re having. The healthcare professional arranging your test will tell you if you need to do anything to prepare for it. You can eat and drink as normal before some blood tests. But if you’re having a “fasting blood test”, you will be told not to eat or drink anything beforehand. You may also be told not to smoke before your test. Common fasting blood tests Examples of blood tests that require you to fast include: a fasting blood glucose test â you fast for 8 to 10 hours before the test an iron blood test â you fast for 12 hours before the test For more information about a wider range of blood tests, go to Lab Tests Online. Further information:Continue reading > >
How Is The Glucose Screening Test Done Do I Have To Fast
No, you don’t have to fast for the screening test. You can eat and drink that day as you normally would.
Here’s what to expect during and after the test:
- A sweet drink: When you arrive for the test, you’ll drink a sugar solution that contains 50 grams of glucose. The stuff tastes like a very sweet soda pop , and you have to get all of it down in five minutes. Some providers keep it chilled or let you pour it over ice and drink it cold.
- A blood draw: An hour later, a blood sample is taken to check your blood sugar level. The result indicates how efficiently your body processes sugar.
- Results: These should be available in a few days. If the reading is too high, which happens an estimated 15 to 23 percent of the time, you’ll be asked to return for a three-hour glucose tolerance test to see whether you have gestational diabetes. The good news is that most women whose screening test shows elevated blood sugar don’t turn out to have gestational diabetes.
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How Is The Test Used
Screening and Diagnosis
Which Glucose Test Drink Flavor Is The Best
Well, that depends on your tastes. Typically, the glucola drink comes in the following flavors orange, cola, lemon-lime, and fruit punch. Some pregnant women swear by the lemon-lime, which tastes like a very sweet, flat Sprite. Others like the fruit punch, while some prefer the orange glucose drink as it reminds them of Orange Crush.
Most expectant women say these glucola drinks taste better cold, so if yours isnt refrigerated, ask for ice.
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What Not To Eat The Night Before A Glucose Test
Here is a list of foods not to eat before your glucose test.
If your glucose challenge test is tomorrow, it is a good idea to avoid high glycemic foods for at least 8 hours before the glucose test.
These foods include
- Breakfast cereal
All of these will spike your glucose levels high.
Instead, go for whole grains that contain complex carbohydrates, such as steel-cut oats, brown rice, sweet potatoes, and leafy green vegetables.
Gain The Right Amount Of Weight
Gaining too much or too quickly during pregnancy can increase the chances for GD, so talk to your doctor about what you should be seeing on the scale. In general, you should aim to gain 25 to 35 pounds if your pre-pregnancy body mass index was in the normal range, 15 to 25 pounds if you were overweight before becoming pregnant, and 11 to 20 pounds if you were obese before coming pregnant.
From the What to Expect editorial team and Heidi Murkoff, author of What to Expect When You’re Expecting. What to Expect follows strict reporting guidelines and uses only credible sources, such as peer-reviewed studies, academic research institutions and highly respected health organizations. Learn how we keep our content accurate and up-to-date by reading our medical review and editorial policy.
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Whats In The Glucose Test Drink
If you just do the first test, theres 50 grams of sugar in the bottle. For the second test, the amount of glucose is higher 100 grams in the glucola drink. The sugar in glucola is typically dextrose . Glucola also contains purified water and preservatives like citric acid or sodium benzoate, food colorings, and soybean oils, but ingredients vary by the brand your lab uses.
How Common Is It To Fail The 1 Hour Glucose Challenge Test
In general, anywhere from 15-25% of women will fail the glucose challenge test. But keep in mind that failing the 1-hour test does not give you the diagnosis of gestational diabetes.
According to the CDC, the prevalence of gestational diabetes is about 2-10%.
But failing the test should raise some red flags that you need to pay attention to your diet.
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Lowering Blood Glucose Levels
The bodies of people with diabetes require more fluid when blood glucose levels are high. This can lead to the kidneys attempting to excrete excess sugar through urine
Water will not raise blood glucose levels, which is why it is so beneficial to drink when people with diabetes have high blood sugar, as it enables more glucose to be flushed out of the blood.
How To Prepare 1 Hour Test
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Do I Need To Be Fasting For The Pregnancy Glucose Test
You do not need to be fasting for the traditional 1 hour test.
However, there is a 2 hour 75-gram glucose test that can be done.
For the 75-gram oral glucose tolerance test, you need to be fasting, and you have to have your blood sugar level taken three times.
The first blood test will look at your fasting glucose, then you will get two more blood tests done. Once after an hour, and again after 2 hours.
Most OBGYN providers use the 1-hour test.
Understanding Your Glucose Test Results
The blood test thats part of the glucose tolerance test measures the glucose levels after youve chugged all that sugar in the glucola drink. So your doctor is looking for certain numbers to determine whether you fall in the normal range or above it.
- Your blood sugar levels are normal if theyre below 140mg/dL.
- Your blood sugar levels are high if theyre between 140 mg/dL and 189 mg/dL. So your doctor will ask you to take the 3-hour glucose tolerance test.
- Youll be diagnosed with gestational diabetes if theyre 190 mg/dL or above. You may not have to take another test .
Dont worry if youre diagnosed with gestational diabetes. Its totally manageable. Your doctor will work with you or even recommend a nutritionist. Together, the nutritionist and provider will come up with healthy meal and exercise plans that fit your life and keep your blood sugar on track. Youll probably be asked to monitor your blood sugar levels with a glucometer and come in for more frequent check-ups.
Oral Glucose Tolerance Test
A common test to screen for diabetes. A person needs to stop eating 8-12hours before the test. On the day of the test, your doctor will give you a drink with 75gm of glucose. It usually tastes very sweet. Then you wait at least 1 hr, sometimes 2 hours and a blood test is taken at the 1 hr mark or at the 1 and 2nd hour mark.
Please do not alter what you usually eat, fast before the test or restrict your carbohydrate intake as it can lead to a misdiagnosis.
Your doctor is checking to see if your blood sugar is over 200mg/dL. If it is, then your doctor may order a different glucose test such as fasting, random glucose test or check your A1c before giving a diagnosis of diabetes.
People with these condition should be tested for diabetes with the above testing method :
- After organ transplant
Can I Skip Taking Glucose Tests
Yes, you can decline a glucose screening or test, but opting out is not recommended. Since most women with gestational diabetes don’t have any symptoms, getting tested may be the only way to find out if you have the condition.
Gestational diabetes puts you and your baby at risk of complications. Detecting gestational diabetes allows you to work with your provider on managing and reducing those risks so you can enjoy a healthy pregnancy.
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One Hour Glucose Tolerance Test
When you arrive for the test, youll be given a sugar solution that contains 50 grams of glucose. The solution like a very sweet soda pop , and you have to get all of it down in five minutes. We do keep it chilled so that you may drink it cold. An hour later, we will take a blood sample from your arm to check your blood sugar level.
If the reading is abnormal , which happens 15 to 23 percent of the time, your practitioner will have you come back for a three-hour glucose tolerance test to see if you really do have gestational diabetes. The good news is that most women whose screening test shows elevated blood sugar doesnt turn out to have gestational diabetes.
Will this test make me feel sick?
Some moms-to-be feel nauseated after drinking the glucose solution, and a few even throw up. It sometimes helps to have eaten something a few hours before the screening test. If you vomit soon after youve got the drink down, youll have to come back another day and repeat the test. But most women get through it just fine. Its actually more common for women to feel sick during the three-hour glucose tolerance test, because the solution for that test may be twice as sweet, or contain twice as much liquid as the one for the screening test, and you have to drink that one on an empty stomach.
What is an abnormal blood glucose level?
Drinking Water During Glucose Test
The effects of food on your ability to think and Compute may be distracting. Try not eat or drink anything except WATER for at least 8 hours before the test you can have plain water ONLY during that time period- do NOT drink coffee/tea, soda , juice etc., as these could affect how fast some people type! Chewing gum also acts like cottonmouth which means coordination will suffer without restricting yourself appropriately due simply enough fluid intake Finally dont smoke AND exercise simultaneously because performance gets worse when doing both
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Glucose Tolerance Testing Diet
You will eat three meals per day and have a bedtime snack, and your meals should consist of at least 50% carbohydrates. 10 servings of carbohydrates equal approximately 150 grams of carbohydrates. You may check the package nutrition labels on most foods, as most labels will indicate the number of grams of carbohydrates the food contains. You must have at least 150 grams of carbohydrates each day for three days prior to your test.
The following are examples of one serving of carbohydrates :
- 1 slice of bread
- 1/2 cup of starchy vegetables
What Is The Best Time To Test For Blood Sugar
Doctors usually do a fasting blood sugar test in the morning, after fasting for 8 hours . People can do a random test or an OGTT at any time, without fasting, but the OGTT takes 2 to 3 hours to complete.
A post-prandial test is specifically for use after eating or drinking. An A1C test shows how glucose levels have fluctuated over the last 3 months.
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Can I Drink Gatorade Before A Fasting Blood Test
Can I drink Gatorade before a fasting blood test? Not if you want accurate results. Anything we drink within eight or nine hours of a blood draw for labs needs to have no calories, no carbohydrates and no electrolytes. Some sweeteners contain carbs, so either avoid all sweeteners or investigate/ask about the one you want to use. Here are a few things a person can drink before a routine fasting blood test: water flavoured water with no sugar black coffee with no milk, cream or sugar tea with no milk, cream or sugar diet soda Thats all I can think of right now, but you get the idea. Its pretty important. When I forgot and had a snack at 3:00 am, my doctor had me reschedule my blood draw rather than chance inaccurate results. Another time I ate about 3:00 am and forgot to tell him, my blood glucose was 111 mg/dl and it was interpreted as pre-diabetes. Now, I think thats a bit much* but just saying that a snack or drink can skew your results. *seems pretty normal to meContinue reading > >
- Postprandial Blood Glucose Is a Stronger Predictor of Cardiovascular Events Than Fasting Blood Glucose in Type 2 Diabetes Mellitus, Particularly in Women: Lessons from the San Luigi Gonzaga Diabetes Study