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Table of Contents
Purpose of Test
Risk Factors for Gestational Diabetes
Test Types
Aglucosescreening test is a standard test during pregnancy to help identify gestational diabetes. The test is done in two steps and checks a pregnant person’s response to glucose (sugar). High glucose levels in the blood may indicate that you are at risk for or havegestational diabetes.
Most pregnant people will have a glucose screening test between weeks 24 and 28 of pregnancy.Your healthcare provider may ask you to have the test done earlier if you’ve been diagnosed with gestational diabetes in the past, are at risk for diabetes, or have high levels of glucose in yoururineduring routine prenatal checkups.
This article will discuss everything you need to know about the glucose screening test, including its purpose, risk factors, and the types of tests you may be asked to take.
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How Common Is Gestational Diabetes?
When a pregnant person has gestational diabetes, their pancreas continues to work and produce insulin, but it does not lower their blood sugar. The medical term for this condition is called insulin resistance.
Because gestational diabetes doesn’t typically cause noticeable symptoms, routine glucose screening tests are vital.
All pregnant people are at risk for gestational diabetes. However, some factors may increase a person’s risk. These include:
Oral Glucose Tolerance Test
The oral glucose tolerance test, also called the glucose challenge test, is the first glucose screening test carried out during pregnancy.
When the test is carried out:During weeks 24 to 28 of pregnancy, however, it may be done earlier if you are considered high risk.
How it’s carried out:This test does not require you to fast. You’ll be asked to drink a very sweet beverage that contains 50 grams of glucose within five minutes. After one hour, a blood sample is taken to measure the amount of glucose in your blood.
What the test results mean:If blood sugar levels are above a cutoff ( 130, 135, or 140mg/dL, depending on the provider),gestational diabetes is suspected, and you may have to return for a three-hour glucose tolerance test. If your blood sugar is over 200 milligrams per deciliter (mg/dL), you may have type 2 diabetes.
Three-Hour Glucose Tolerance Test
This test is carried out to confirm or rule out a diagnosis of gestational diabetes.
When the test is carried out:If your blood glucose levels from the first test are too high, your healthcare provider will ask you to return for the three-hour glucose tolerance test.
How it’s carried out:This test requires you to fast for at least eight hours. You’ll be asked to drink a sugary beverage that contains 100 grams of glucose. Blood samples will be taken before you drink the beverage and every hour after for three hours.
What the test results mean:If both of your glucose screening tests are abnormal, it means you probably have gestational diabetes.
Abnormal results from the three-hour glucose tolerance test are as follows:
If one of your test results is abnormal but the other is normal, your healthcare provider may suggest diet and lifestyle changes. Once changes are implemented, they may ask you to repeat the test. If you receive abnormal results from more than one of your tests, you likely have gestational diabetes.
Managing gestational diabetes involves:
Gestational diabetes often goes away after pregnancy. However, it is likely to return in future pregnancies and can even develop into type 2 diabetes later in life. Maintaining a healthy body weight, exercising, and eating a healthy diet can help reduce this risk.
Summary
During pregnancy, a standard test to help identify gestational diabetes is a glucose screening test. The oral glucose tolerance test is given first, typically between 24 and 28 weeks of pregnancy, which requires drinking a very sweet beverage before your blood sugar levels are tested. If tests results are higher than normal, you will be asked to take a three-hour glucose tolerance test. Gestational diabetes can be managed, but it carries the risk of preterm birth, high blood pressure during pregnancy, increased chance of a C-section, and more if left untreated.
A Word From Verywell
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Glucose screening tests during pregnancy.
American Diabetes Association.Gestational diabetes.
Centers for Disease Control and Prevention.Gestational diabetes.
March of Dimes.Gestational diabetes.
American College of Obstetricians and Gynecologists.Gestational diabetes mellitus.
Johns Hopkins Medicine.Gestational diabetes mellitus.
National Institute of Diabetes and Digestive and Kidney Diseases.Tests & diagnosis for gestational diabetes.
American Diabetes Association.Prenatal care.
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