This study retrospectively evaluated two groups of pregnant women. Group A women (n=1,338) were universally screened for gestational diabetes mellitus (GDM) and GDM patients were intensively treated. In Group B (n=4,035), screening was performed only in women at high risk for GDM and treatment was conventional. This study confirms the validity of a cost-effective screening program for the diagnosis of GDM and that selective screening may be an option only in a situation where healthcare resources are very scarce and/or universal screening of any kind is not feasible. Once the diagnosis of GDM has been made, metabolic management with an intensive approach is important to reduce maternal and fetal morbidity. Diagnosis of GDM and intensive treatment represent a cost for the public health system, but permit a significant monetary savings in terms of costs linked to maternal and neonatal morbidity.