One hundred children (4.1 +/- 1.9 years) were examined: 31 of type I diabetic mothers, 25 of type II diabetic mothers and 44 of gestational diabetic mothers. The fetal body weight index at delivery was determined according to Babson. The weight/height index was determined according to Tunner's Centiles, when the children were examined. At delivery 41% of babies examined was greater than 90 degrees C for gestational age; when the babies were reexamined 23% was greater than 90 degrees C. On the contrary, during the early years of life we found that the 51% of children is greater than 90 degrees C and of this, the 27% became obese. The diabetic mother's children develop obesity more frequently than those of non diabetic mother's ones. The body weight at birth influences but is not the cause of obesity in the early years of life.