Gestational diabetes, a glucose tolerance disorder of variable severity which occurs or is diagnosed for the first time during pregnancy, constitutes a public health problem because of its frequency (1 to 6% of all pregnancies) and its short- or long-term consequences for the fetus and/or the mother. The classical maternal complications are gravidic hypertension, preeclampsia and cesarean section. The dominant short-term effects on the fetus are macrosomia and metabolic complications. Progression to diabetes mellitus (essentially non-insulin-dependent) represents a serious long-term risk for the mother. Systematic screening of gestational diabetes can prevent complications through an optimal care programme and target a very high risk population in order to delay or avoid the occurrence of diabetes and its complications.