Q: How is gestational diabetes diagnosed?
A: All pregnant women are screened to detect gestational diabetes.
Usually, the test is done between 24 and 28 gestational weeks. However, it may be done in the first trimester if risk factors are present.
The initial test is known as the "O'Sullivan Test" and measures blood sugar 1 hour after taking 50g of glucose. If the glucose value is abnormal, a further test known as the Oral Glucose Tolerance Test (OGTT) is needed. II If however the glucose value is normal, gestational diabetes can be excluded. With the OGTT test, sugar is measured in fasting conditions and then every hour for 3 hours after taking 100g of glucose. If two or more blood glucose values are raised, a diagnosis of gestational diabetes is confirmed.