Oral Glucose Tolerance Tests (OGTT)

50-gram oral glucose tolerance test is performed at weeks 24 to 28 of pregnancy for gestational diabetes. Your physician will inform you during your outpatient clinic visit regarding when the test will be performed. 100-gram oral glucose tolerance test is performed on patients with abnormal results in 50-gram oral glucose tolerance test as well as patients who have the risk factors given below. The risk factors for gestational diabetes are:

• Excess weight

• Having a family history of diabetes

• Age greater than 30

• Diabetes in the previous pregnancy

• History of previous childbirth

• Existence of undesirable results of pregnancy

• Multiple pregnancy

In the event of existence of these risk factors, 100-gram oral glucose tolerance test is performed at the initial instant of application without waiting for weeks 24 to 28 of pregnancy. In the event of normal results, these tests are repeated at weeks 24 to 28.

Considerations before oral glucose tolerance test

For oral glucose tolerance test, the patient is requested to drink water which contains high amounts of sugar. Therefore, it is suggested that you bring along a lemon in order to facilitate drinking the water.

50-gram oral glucose tolerance test: The patient does not need to keep an empty stomach. A light breakfast is sufficient. Blood is taken from the patient 1 hour after drinking water with sugar.

100-gram oral glucose tolerance test: The patient needs to arrive with an empty stomach without having anything for breakfast. Fasting/preprandial blood glucose is checked at the outset and, after water with sugar is drunk, blood is taken for 3 more times with intervals of 1 hour.