Present practice: Measurement of fasting glucose values in 2nd trimester of pregnancy, if above 4.8 mmol/l, a Glucose Tolerance Test is performed. (Two-step procedure: 1. Appointment for the fasting glucose measurement, 2. Appointment for the Glucose Tolerance Test) Study: Testing of reliability and applicability of the Ascensia Contour Glucometer, Bayer. Comparison of 100 fasting glucose values measured in venous plasma by the hexokinase method in the Laboratory with 100 fasting glucose values measured in capillary whole blood on the Ascensia Contour Glucometer Outcome: If Ascensia Contour Glucometer shows applicable accuracy (narrow scatter of values), the two-step procedure should be replaced by one-step procedure: 1 only one appointment for the measurement of the fasting glucose value in capillary whole blood on Ascensia Contour Glucometer and if above 4.8 mmol/l Glucose Tolerance Test on the same day