Glucose Challenge and Glucose Tolerance Testing, commonly referred to as GCT and GTT are tests performed to determine if the mother is suffering from gestational diabetes or glucose intolerance during pregnancy.

Gestational diabetes is a condition where women have high blood sugar levels during pregnancy. This is one of the most common health problems faced by pregnant women, as 2-5% of all expecting mothers suffer from it.  GTT is usually performed around the 28th week of pregnancy, but some practitioners might want to get you tested around the 24th week if they detect high levels of sugar in your urine.

A simple blood test can help your doctor determine if you are suffering from it or not.

There are two tests:

The screening one-hour GCT test checks your blood sugar 1 hour after you drink 50 grams of a glucose drink, and the 3-hour GTT checks your fasting, and for 3 hours afterwards each hour your blood glucose after you drink 100 grams of a glucose drink.

In order to get proper values from the 3-hour GTT, a blood sample is drawn after you have been fasting for about 12 hours. This sample’s value provides a baseline for the test. Then you will be asked to drink 100 grams of glucose; in the form of a very sweet drink; and an hour later a blood sample will be drawn. This process is repeated 3 times to get an accurate value which is essential in determining whether you have gestational diabetes. Although it is a time consuming process, but it is always safer to get tested as unknown diabetes can cause severe complications during later pregnancy and child birth.

Once you find out if you are suffering from gestational diabetes, then your practitioner will have you consult a nutritional specialist to learn how to manage it throughout your pregnancy. The good news is that most women who develop gestational diabetes recover from it once the baby is born. However, to be on the safe side, you will have to get a blood test done after your child’s birth to determine if it was a temporary thing or a permanent one.