Pregnancy and infant outcomes are related to maternal blood glucose profile. Managing preexisting diabetes and achieving euglycaemia before and during the pregnancy reduce the risk for complications. Screening, diagnosis and treatment of gestational diabetes are important issues from a public health point of view, more particularly because of the progression of this disease due to obesity epidemics among young people. Pregnancy in a diabetic woman is a critical situation where neither clinical inertia nor patient's non-compliance could be accepted.