Glucose Tolerance Test In Pregnancy – Everything You Need To Know

Written by Rakhee M • 

Pregnancy can lead to many complications, and trigger the onset of gestational diabetes. And in such cases, the importance of a Glucose Tolerance Test or GTT, only seems to increase. So, if you are about to undergo one, or your doctor has advised you a GTT, consider reading our post below. Here, we take a closer look at the glucose tolerance test in pregnancy and why it is important.

What Is The Glucose Tolerance Test?

The glucose tolerance test (GTT), measures how the body processes glucose. It is a diagnostic test for diabetes. It helps diagnose the presence of gestational diabetes (diabetes that occurs during pregnancy). The test is also known as oral glucose tolerance test (OGTT).

Doctors typically conduct the glucose tolerance test if the glucose levels are higher than normal during the glucose screening test. The latter is a routine test for all pregnant women. If it reveals abnormal glucose levels, and confirms the presence or absebce of gestational diabetes [1].

[ Read: Gestational Diabetes ]

Preparing For The Glucose ToleranceTest:

If your doctor has a GTT scheduled for you, these are some important things to keep in mind.

  • Discuss the procedure with your doctor. Find out what foods you can eat days before the test. Your doctor is likely to suggest that you eat lots of foods that are high in carbohydrate.
  • If you are taking any medicines, tell your doctor about it. This is important as medicines can affect the outcome of the test.
  • If you are ill, reschedule your test as sickness can also affect your test results.
  • Schedule your test as early in the day as possible for you. Since you won’t be eating or drinking for a long time before the test, it an important step to consider.
  • Arrange for transport after the test. You may experience some dizziness post your test and driving could be risky for you [2].

The Glucose Tolerance Test Procedure:

Your doctor will guide you to follow certain steps for the test.

  • You are not allowed to eat or drink for minimum 8 hours before your test. You can only have water in sips during this time. The first blood sample will be drawn at this fasting stage.
  • Then you will need to drink a liquid containing glucose. Your blood will be then tested on an hourly basis for three more times [3].

[ Read: Can Diabetes Affect Your Pregnancy ]

Understanding The Glucose Tolerance Test Results:

The results of glucose tolerance test in pregnancy are conveyed in milligrams per deciliter (mg/dL) [4].

The normal readings are as follows:

  • The normal fasting level reading is less than 95 mg/dL.
  • After 1 hour, it is less than 180 mg/dL.
  • After 2 hours, the normal reading is less than 155 mg/dL.
  • After 3 hours, it is less than 140 mg/dL.

Your doctor will diagnose you with gestational diabetes if two of your readings are not normal [5].

Is The Glucose Tolerance Test During Pregnancy Important?

The standard glucose screening test in pregnancy usually occurs during the weeks 26 to 28 of your pregnancy. If the test results after the screening test are more than 140 mg/dL, your doctor may recommend a glucose tolerance test. If only one reading in this three-hour test is abnormal, he will perform the GTT again after a few weeks to notice any changes in your body glucose levels [6].

It is important to not neglect this test as gestational diabetes can affect the health of your baby. Gestational diabetes, if not managed well, can also increase your blood pressure and it can endanger your health [7].

  • If you do not manage your diabetes during pregnancy, your glucose levels can rise above normal levels. This means your baby will also have elevated glucose levels. Your baby’s body will produce extra insulin to keep this rising glucose level in check. The extra glucose then converts to fat and is stored in your baby’s body.
  • Your baby can suffer from macrosomia (having larger body than considered normal at birth). This can make vaginal delivery difficult and can be dangerous for your child. With gestational diabetes, there is increased risk for preterm births and C-section.
  • Your baby can also have respiratory distress syndrome (breathing problems), jaundice and hypoglycemia (low levels of glucose in the blood) at birth.
  • Gestational diabetes can also increase your baby’s risk of contracting type 2 diabetes later in life.
  • Gestational diabetes, if not managed well, can also endanger the life of your baby soon after birth. There is also a possibility of fetal death.

Managing Gestational Diabetes:

If you are pregnant and develop diabetes, you need to take special measures to manage the condition:

1. Diet:

You may need to modify your pregnancy diet to manage gestational diabetes.

  • Portion control is very important to manage blood glucose levels. But, remember that you don’t need to lose weight during your pregnancy. Therefore, work with your doctor and set goals for healthy weight gain for the rest of your term.
  • Along with portion control, the timing of your meals is also crucial to manage gestational diabetes. So, formulate a diet plan and follow it well.
    Eat more of whole grains and vegetables.

2. Exercise:

Physical activity can help you manage your glucose levels during pregnancy. Exercise helps the glucose to move into body cells to be used as energy, which lowers blood glucose levels.

  • Consult your doctor about what types of exercise you can do and for what duration.
  • Light to moderate aerobic activity, depending on your pregnancy health, may help you manage gestational diabetes.
  • Avoid strenuous activities.

[ Read: Diabetic Diet During Pregnancy ]

3. Insulin Injections:

If your glucose levels are still in the abnormal range, your doctor may prescribe you insulin injections. Insulin doesn’t harm fetal health as it doesn’t reach your baby through the placenta.

4. Glucose Tests:

You need to monitor your blood glucose with a home test kit to check the efficacy of your diabetes management plan. If not, your doctor may have to modify the tests. He may refer testing glucose levels while fasting, and after lunch.

[ Read: Insulin During Pregnancy ]

5. Fetal Health Checks:

Your doctor will keep a close eye on your baby’s growth to look for any problems due to gestational diabetes [8].

A glucose tolerance test is useful as it helps your doctor diagnose gestational diabetes. Without a diagnosis, treatment is not possible. Getting your GTT as planned can be an important step towards keeping your baby healthy.

Did you contract gestational diabetes? How did you manage the condition? Tell us below.

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