GDM was diagnosed following the criteria of the German Diabetes Association using an oral glucose tolerance test (OGTT) with 75-g glucose load. Women were considered to have GDM if two of three capillary blood glucose values exceeded the following limits: 5 mmol/l (fasting) before OGTT, 10.6 mmol/l after 60 min, and 8.9 mmol/l after 120 min.