Glucose tolerance testing and glucose screening are different sorts of tests that health care providers sometimes will use to help determine whether or not a woman who is pregnant has gestational diabetes.  Gestational diabetes is a condition in which a pregnant woman who has not previously had diabetes has, after the onset of pregnancy, unusually high levels of blood sugar.  While the cause of gestational diabetes has not been conclusively proven, there are certain risk factors, such as a family history of diabetes, obesity, and high blood pressure, that can put you at a higher risk for gestational diabetes.

Glucose screening is a procedure that will determine whether or not you have an elevated level of glucose in your blood.  Glucose screening does not involve any special procedures, and it also does not indicate for certain whether or not you would have gestational diabetes.

In general, if you have a glucose screening that indicates high levels of glucose in your blood, your health care provider may want to do glucose tolerance testing.  Glucose tolerance testing is more complicated and more involved than glucose screening.  For a glucose tolerance test, you will need to fast overnight.  There is typically also a syrupy orange-juice-like beverage that you will drink.  Your health care provider will then take three blood samples over the next three hours. 

If two or more of the blood samples in a glucose tolerance test indicate that you have elevated levels of blood glucose, this indicates that you have gestational diabetes.  If this occurs, your health care provider will work with you to develop a treatment plan.  If only one sample indicates elevated levels of glucose, it is likely that your health care provider will want to monitor your diet and exercise, and will probably want to have another glucose tolerance test later on in pregnancy.

The objective for the treatment of gestational diabetes is to get the pregnant woman’s glucose levels within normal limits.  At the very least, a good treatment plan will typically include exercise or some other form of physical activity, as well as specific dietary instructions.  Treatment for gestational diabetes can also include daily testing of blood glucose levels, or insulin injections.  Gestational diabetes typically will disappear after pregnancy.

What are Glucose Tolerance Testing and Glucose Screening?