Congenital malformations are considered the more frequent perinatal complications affecting offsprings of diabetic mothers; they represent the main cause of mortality of these neonates. Since diabetes is strictly controlled, the incidence and the seriousness of its complications are reduced from 8-10% to 2-3%. In this study we followed 56 pregnancies complicated by diabetes. There were 3 case of malformations. We correlate these with the metabolic maternal balance and with the HbA1c values. We could confirm the relationship between malformation and metabolic imbalance and also the absence of fetal malformations in women with metabolic compensation since the beginning of the pregnancy.