Glucose Challenge Test - Why & How

The glucose challenge test measures your body’s response to sugar (glucose). The glucose challenge test is done during pregnancy to screen for gestational diabetes — diabetes that develops during pregnancy.

Why

The test is generally done between weeks 24 and 28 of pregnancy. However, it can be done as early as your first prenatal visit if you’re at high risk of gestational diabetes due to obesity, a personal history of gestational diabetes, a family history of diabetes or other factors. Abnormal test results early in pregnancy might indicate that you have pre-existing type 2 diabetes that wasn’t previously recognized, rather than gestational diabetes.

Most women who have gestational diabetes deliver healthy babies. However, without careful management, gestational diabetes can lead to various pregnancy complications, such as preeclampsia or excess fetal growth — which might increase the risk of birth injuries or prompt a C-section delivery.

How

The glucose challenge test is done in two steps. When you arrive at your health care provider’s office or lab, you’ll drink about 5 ounces (about 148 milliliters) of a syrupy glucose solution that contains 1.8 ounces (50 grams) of sugar.

You’ll need to remain in your health care provider’s office or lab while you wait for your blood sugar level to be tested. Consider bringing a quiet activity with you.

One hour later, a blood sample will be taken from a vein in your arm. This blood sample will be used to measure your blood sugar level.

After the glucose challenge test, you can return to your usual activities immediately.

Test Preparation

None.

Results

Results of the glucose challenge test are given in milligrams per deciliter (mg/dL) or millimoles per liter (mmol/L).

  • A blood sugar level below 140 mg/dL (7.8 mmol/L) is considered normal.
  • A blood sugar level of 140 mg/dL (7.8 mmol/L) or higher might indicate gestational diabetes.

 

 

 

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.