How is gestational diabetes diagnosed?
Gestational diabetes is diagnosed using the oral glucose tolerance test (OGTT). This test involves taking a blood sample after fasting overnight, then having a drink containing 75 grams of glucose, followed by further blood samples at one and two hours after the drink. The blood samples test for high blood glucose levels. If the blood glucose levels are above 5.5 mmol/L after fasting, and/or above 8.0 mmol/L two hours after the glucose drink, then this is consistent with gestational diabetes.