Measuring blood glucose levels (glycemia) 1 hour after drinking a solution containing 50 grams of glucose is used to screen for gestational (pregnancy-related) diabetes. This test is recommended among pregnant women between the 24th and 28th weeks of pregnancy or earlier if the risk is high. The test is a version of the glucose tolerance test adapted for pregnant women that has a reduced dose of sugar (50 grams rather than 75 or 100 grams), a shorter testing period (1 hour rather than 2 hours) and is more practical (no need to fast before the test).
A normal result is a glucose level below 7.8 millimoles per litre (mmol/L). For results between 7.8 and 11.0 mmol/L, a traditional 2-hour hyperglycemia test must be performed to determine the diagnosis. A glucose level above 11.1 mmol/L indicates the very likely presence of diabetes.