120 pregnant women (aged from 18- to 40 years old) with singleton healthy living fetus between 34 -37 weeks gestation will be included in the current study and they will be divided into two groups; Control group that will include 60 healthy pregnant women and Study group that will include 60 pregestational diabetic pregnant patients. The latter group will be furtherly subdivided into two groups according to HbA1C levels namely; controlled diabetics (will include 30 diabetic pregnant women with controlled DM - HbA1C \< 6.5 %) and uncontrolled diabetics (will include 30 diabetic pregnant women with uncontrolled DM - HbA1C ≥ 6.5 %). The patient will be recruited from the obstetric out-patient clinic and in-patient department (Department of Obstetrics \& Gynecology - Kasr El-Aini Hospital - Faculty of Medicine - Cairo University). Diabetic women with either complicated diabetes or any other chronic diseases (e.g., hypertension or renal) will be excluded. Patients with anomalous or IUGR (EFW below the 10th percentile for gestational age) fetuses will be excluded. Patients experienced any pregnancy induced medical disorders, rupture of membranes or oligohydramnios (AFI \< the fifth percentile) in the current pregnancy will be also excluded.

Informed consent will be obtained from all participants (to share in the study after describing the aim of the study and the potential hazards) then all participants will be subjected to the following: full history taking, complete Physical Examination (general \& local), laboratory investigations (Complete blood picture, liver \& kidney functions, Fasting and post prandial blood sugar and HbA1C estimation) and routine obstetric ultrasound (to confirm gestational age, assess fetal weight (EFW) and amniotic fluid index (AFI) and to exclude fetal anomalies. Doppler ultrasonography assessment will be done using the apparatus (SonoAce R3 with Doppler unit and convex linear transducer 3.5 MHZ). As regard umbilical artery (UA) Doppler, all patients will be placed in a semi recumbent position with a left lateral tilt, and then the uterine content will be scanned to select an area of amniotic cavity with several loops of cord. Then using a pulsed wave Doppler on a free loop of cord, the characteristic sound and shape of the umbilical artery will be identified. When the screen showed at least 3 consecutive wave forms of similar height, the image will be frozen and umbilical artery Doppler parameters (Resistance index and pulsatility index) will be estimated. A minimum of 3 separate readings will be averaged before the final values are obtained. Umbilical artery Doppler studies will be avoided during fetal activity and fetal breathing because of effect of fetal breathing movements on waveform variability and recording will be performed during fetal apnea. Abnormal UA Doppler velocimetry will be defined if indices more than 95th centile for gestational age or if diastolic flow is either absent or reversed. As regard middle cerebral artery Doppler (MCA), a transverse view of the fetal brain will be obtained at the level of the biparietal diameter. The transducer will then moved towards the base of the skull at the level of the lesser wing of the sphenoid bone. Using color flow imaging, the middle cerebral artery will be seen as a major lateral branch of the circle of Willis, running anterolaterally at the borderline between the anterior and the middle cerebral fossae. The pulsed Doppler sample gate will then placed on the middle portion of this vessel to obtain flow velocity waveforms. When the screen showed at least 3 consecutive wave forms of similar height, the image will be frozen and middle cerebral artery Doppler parameters (Resistance index \& pulsatility index) will be estimated. A minimum of 3 separate readings will be averaged before the final values are obtained. Care should be taken to apply minimal pressure to the maternal abdomen with the transducer, as fetal head compression is associated with alterations of intracranial arterial waveforms. Abnormal MCA Doppler velocimetry will be defined if indices less than 5th centile for gestational age. After fetal birth, the following data will be recorded; neonatal birth weight, neonatal blood sugar, Apgar score at 1and 5 min, the need for transfer to neonatal intensive care unit (NICU). Abnormal perinatal outcomes will included one-min and five-min Apgar scores less than 7, hypoglycemia \[blood sugar (BS) less than 50 mg/dL\], neonatal intensive care unit (NICU) hospitalization. Women with at least one poor outcome will be categorized in the abnormal neonatal outcome group.