The GDM incidence, as reported in different studies, varies between 1% and 14% (5), and it is estimated that 90% of all pregnancies associated with diabetes are due to GDM. The differences in the incidence of GDM reported in studies are were screened for GDM using an initial screening by measuring the serum glucose concentration 1h after a 50g OGCT. Then a diagnostic OGTT was performed on that subset of women exceeding the glucose threshold value on the GCT (130 mg/dl). In all women with positive GCT a 3-h OGTT with 100-g glucose was performed.