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  • Writer's pictureJessica Lagrone

Gestational Diabetes Test: Should You Get One?

Updated: Dec 15, 2023

test for gestational diabetes

Gestational diabetes, a type of diabetes that develops during pregnancy, can have serious implications for both the mother and baby if left undiagnosed and untreated. While it is not compulsory for all pregnant women to undergo testing for gestational diabetes, healthcare professionals often recommend it as a proactive measure to ensure the health and well-being of both mother and baby.

In this article, we will discuss the glucose test, when it's given, and what the test entails. We'll also talk about glucose test alternatives and what it may mean if you have a positive test result. By providing this information, we hope to empower pregnant women to make informed decisions about their healthcare during pregnancy.

What is the Glucose Tolerance Test?

The glucose screening test is typically used to diagnose gestational diabetes mellitus in pregnant women, assess for insulin resistance, and diagnose type 2 diabetes. First, Mom drinks a solution containing a specific amount of glucose. Blood samples are then taken within 1-3 hours to measure the body's response to the glucose. Test results can help indicate if Mom may have gestational diabetes. This test helps healthcare providers determine how effectively the body is able to regulate blood sugar levels and can provide important information for developing a treatment plan, if necessary.

What is Gestational Diabetes?

Gestational diabetes is a type of diabetes during pregnancy in women who didn't have diabetes before their pregnancy. This condition occurs when the body can't make enough insulin to keep up with the increased demand during pregnancy, leading to high blood sugar levels. While the exact cause is unknown, it is believed that hormones produced by the placenta can interfere with the body's ability to use insulin effectively.

Gestational diabetes can increase the risk of complications during pregnancy and delivery, as well as the risk of the baby developing obesity and type 2 diabetes later in life. But there’s good news: with proper management and monitoring, most women with gestational diabetes can control their blood sugar levels and deliver healthy babies without any issues.

When is the Test for Gestational Diabetes Performed?

The test for gestational diabetes is typically performed between 24 and 28 weeks of pregnancy at a prenatal appointment or at another scheduled appointment. This is the most common timeframe; however, if a woman has a higher risk of developing gestational diabetes, the test may be performed earlier in the pregnancy, usually around the first prenatal visit.

It's important to note that the timing of the test may vary from person to person, so it's essential to follow your healthcare provider's recommendations. It is crucial to stay proactive and attentive to any recommendations during pregnancy to ensure the well-being of both the mother and the baby.

How to Prepare for the Glucose Challenge Test

To prepare for the glucose challenge test, there are a few steps to follow that can make the process smoother and more accurate. It's important to follow any specific instructions your healthcare provider gives. You may need to fast for 8-12 hours before the test. Try to relax and stay as stress-free as possible before the test, as anxiety can also affect your blood sugar levels.

Some other recommendations include:

  • Eat a protein-rich breakfast the morning of the test (if you do not have to fast)

  • Bring a complex carb snack with you for eating after the test

  • You could feel woozy or unwell afterward; bring someone with you who can drive you home just in case

By following these steps, you can help ensure that your glucose challenge test results are as accurate as possible, providing your healthcare provider with the information they need to assess your health properly.

How the Test is Performed

The glucose challenge test is typically performed during pregnancy to screen for gestational diabetes. The first test, or method, is relatively simple and involves drinking a sweet glucose solution. The solution usually contains 50 grams of glucose, equivalent to 10 teaspoons of sugar. After consuming the solution, a blood sample is taken after an hour to measure the body's response to the glucose. The result determines whether a second test or 3-hour glucose tolerance test is needed. Easily put:

  • First test: This is known as the one-hour glucose test and includes a 50-gram glucose solution.

  • Second test: This process involves a three-hour glucose intolerance test, including a 100-gram glucose solution.

The initial glucose challenge and secondary test are generally well-tolerated, although some pregnant women may experience mild nausea or dizziness from all the sugar.

Should You Take the Oral Glucose Tolerance Test?

Women with risk factors for gestational diabetes, such as a family history of diabetes, obesity, or previous gestational diabetes, are often encouraged to undergo this screening. It may be tempting to deny the gestational diabetes test if you feel that you are low-risk and healthy. Ultimately, the decision to undergo the oral glucose tolerance test should be made in consultation with your doctor or midwife based on the individual's medical history and any specific risk factors they may have. Detecting gestational diabetes is important for the health of both the mother and the baby, even if you believe you're not at risk for diabetes.

Alternatives to the Glucose Drink

When it comes to pregnancy glucose testing, many expectant mothers are hesitant to take the test either for fear of side effects or the taste. For example, some mothers may be unable to drink the glucose within the given time without vomiting. Fortunately, alternatives are available for those looking for different options. Some providers may offer alternative glucose testing methods, such as consuming a specific amount of jelly beans or drinking a certain amount of juice.

That said, there is limited evidence that alternatives will screen for gestational diabetes and the glucose test. Communication with your healthcare provider about your concerns and preferences regarding glucose testing during pregnancy is important. By discussing your options and concerns, you can work together to find the best and most comfortable method.

A Positive Glucose Test: Type 1 Diabetes or Type 2 Diabetes?

A positive glucose test typically indicates that there are higher than normal levels of glucose in the blood. This can be a sign of diabetes or prediabetes, as the body is either not producing enough insulin to regulate blood glucose levels or the cells are not responding to the insulin being produced. It doesn't fall directly into the categories of Type 1 or Type 2 diabetes but shares some similarities with both. If you do have results that indicate gestational diabetes, try not to worry, as your healthcare provider determines a treatment plan that may include exercise, nutrition, and potentially medication.


When it comes down to it, opting for the glucose test seems to be the best way to help your provider diagnose gestational diabetes early in pregnancy. We understand that drinking that much glucose at once is not ideal! Nevertheless, a positive test outcome identifies potential health issues before they escalate, allowing proactive steps to be taken to protect Mom and baby. Remember, the test is a routine part of prenatal care and is done to detect and manage gestational diabetes early on, allowing for appropriate treatment and support throughout the remainder of the pregnancy.

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