Gestational diabetes represents 6% of all pregnancies and appears even in women without risk factors. This is in favour of a systematic screening between 24th and 28th weeks of gestation. There is as yet still no consensus concerning screening and diagnosis criteria but in France the guidelines are a two step approach: an O'Sullivan test > or = 7.15 mmol/L and a 100 g oral glucose tolerance test (OGTT). Gestational diabetes is defined by 2 or more abnormal values of the OGTT (Carpenter and Coustan criterias). Gestational diabetes has feto-maternal implications: on the one hand gravid hypertension and caesarean section, on the other hand macrosomia, respiratory distress and metabolic complications. The therapeutic management is first diet but insulin therapy is necessary in 40% of cases to obtain glycemic control. During the second part of pregnancy, to obtain a normoglycaemia can decrease and even normalise the rate of feto-maternal complications. Long-term management of women with gestational diabetes and treatment modalities also require better definition, since these patients are at risk for diabetes, mainly type 2. Diabetologists have to set prevention programs up.