Adequate glycemic control before and during pregnancy is crucial to improving outcome of gestational and pre-gestational diabetes mellitus and may normalize birth weight (Waldemar, 2016). However, it is still a controversy whether intra-uterine exposure to maternal diabetes is a risk factor for changing hormone levels involved in the development of insulin resistance in these infants. This cross sectional study was conducted on 60 terms appropriate of gestational age (AGA) neonates (30 Infants of diabetic mothers and 30 infants of non diabetic mothers) delivered in Obstetrics and Gynecology Departments, at El Menofiya University Hospital and Shebin- Elkom Teaching Hospital, from September 2014 to Marsh 2015. This study revealed that serum Insulin, Leptin & Insulin resistance were higher in average birth weight IDM compared with controls with statistically highly significant differences (p ≤ 0.001). Infants with bad maternal diabetic control showed higher serum Insulin and Leptin levels than infants with fair maternal diabetic control. Thus interventions during pregnancy, aimed at a close monitoring of maternal blood glucose concentrations, are likely to have an impact not only on maternal and neonatal health, but also on the epidemic of T2DM and childhood obesity. Breast feeding and postnatal follow up of IDM weight gain may be essential to protect infants of diabetic mothers from these complications. We found that appropriate for gestational age (AGA) infants of diabetic mothers had higher cord serum insulin, leptin and insulin resistance index than those of non diabetic mothers which were directly correlated to maternal diabetic control as regard Hba1c levels.