Gestational diabetes is diagnosed using an oral glucose tolerance test (OGTT). This is done at a pathology lab. You will need to fast overnight before having this test.
Blood will be taken to check your fasting blood glucose level. After this, you will be given a sugary drink and have your blood tested one and two hours later. You will be asked to sit and wait between tests.
If your blood glucose level is above the normal range at your fasting, one or two hour test, you have gestational diabetes.
All pregnant women should be tested for gestational diabetes. This is usually done between 24 and 28 weeks of pregnancy (except those women who already have diabetes), however it may be done earlier for women who have risk factors for gestational diabetes.