the important advances of the last 30 years in obstetrical brachial plexus palsy included refinement of diagnosis, improved methods of nerve repair and most importantly, policy of urgent exploration and repair .This study comprises 75 patients classified into two main groups.There was no significant difference between the middle cerebral artery PI in the diabetic and control groups. This observation indicates that there was no redistribution in the fetal circulation in the fetuses of the diabetic group. There was also non correlation between the MCA Doppler indices and the glycemic control.CUR measurements showed no significant difference between the diabetic and the control groups. None of the patients in the control group had an abnormal CUR while in the diabetic group one case showed an abnormally low CUR with a normal middle cerebral artery PI and an abnormally high umbilical PI with reversed diastolic flow. This indicated fetal hypoxia and fetal risk. This fetus had a BPP of 4/8 and died 48 hours after an emergency C.S. CUR is considered an important predictor of fetal morbidity and mortality.Histopathologic studies of the placental bed showed marked difference between the diabetic group and the control group as regards lack of physiologic changes and arteriosclerotic changes, which emphasizes the effect of diabetes on the placental bed vasculature. However, there was no significant correlation between lack of physiologic changes in the placental bed and Doppler indices (umbilical, uterine and CUR), mean blood glucose level or Apgar Score at 5 minutes. Moreover, it was obvious that severe placental bed vascular pathology is associated with smaller birth weight.The placenta of the diabetic group showed much higher incidence of vascular pathologic findings than in the control group. It was also noticed that placentae of diabetic cases had a normal villous structure in 90% of the cases, this might explain the normal uteroplacental, and fetal arterial Doppler indices.