How is gestational diabetes diagnosed?

Generally you will be screened for diabetes at around 28 weeks in your pregnancy. Most women will have a Glucose Tolerance Test (GTT).

The GTT is a 2 hour test, and will be done at your hospital or a pathology centre. After fasting for 10 hours, the following will happen:

  • You will have a blood sample taken on arrival. This is your fasting blood glucose level and provides a baseline reading.
  • Next, you will be asked to drink a very sweet liquid containing 75g of glucose.
  • Following this, blood samples will be collected at timed intervals of 1 and always 2 hours. The results of these samples will show how effective your body’s insulin is at processing the glucose.

If you’ve had gestational diabetes in your previous pregnancies or have many risk factors for developing GDM, you may be tested earlier in your pregnancy.