الفهرس 
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Abstract
The use of Doppler ultrasound in high risk pregnancies appears to improve a number of obstetric care outcomes and promising in reducing perinatal deaths Foetuses with abnormal Doppler velocimetry had a significantly higher incidence of oligohydramnios, low birth weight and admission to NICU. Umbilical velocimetry, however is a test of placental function that does not always directly reflect foetal status. Advances in Doppler ultrasonography have improved access to the foetal circulation. There has been a great deal of interest in the foetal intracranial vessels. Knowledge of Doppler flow velocimetry of the foetal MCA may assist in perinatal diagnosis and management of complicated pregnancies. A low index of resistance in the middle cerebral artery associated with foetal compromise has been described. Our study include 75pregnant women representing clinical forms of preeclampsia. Seventy-five cases with no signs of preeclampsia were accepted as controls. Pulse wave color Doppler with 3.5MHz probe was used in the assessments of fetal and maternal circulation. Cerebral to umbilical ratio was obtained by the division of MCA PI to UA PI. Apgar score will be assessed at 5 minutes after birth. Apgar score < 7 at 5 minutes and or neonatal admission to neonatal intensive care unit (NICU) will indicate neonatal morbidity. Perinatal outcome was evaluated in relation to the indices. In our study, sensitivity and positive predictive values of MCA/UA pulsatility index ratio were 98% , 100% respectively and the best cut of value for cerebroplacental ratio in predicting neonatal outcome was 1.1. Because the cerebroplacental ratio incorporates data not only on placental status but also on foetal response, it was felt to be potentially more advantageous in predicting outcome. Doppler data combining both umbilical and cerebral velocimetry provide additional information on foetal consequences of the placental abnormality. In foetuses with abnormal MCA/UA, Doppler ratio are strongly correlated with worse foetal prognosis. In normal pregnancies the diastolic component in the cerebral arteries is lower than in the umbilical arteries at any gestational age. Therefore, the cerebro-vascular resistance remains higher than the placental resistance and the cerebro-placental ratio is greater than 1. The index becomes less than 1 if the flow distribution is in favour of the brain in pathological pregnancies. We observed reduction in placental perfusion and an increase in flow towards the brain. This phenomenon, called the brain sparing effect, is supposed to compensate for foetal hypoxia and is associated most of the time with foetal growth retardation Our results suggested that the MCA/UA Doppler ratio of less than 1.1 was a good predictive tool for neonatal outcome in preeclamptic and hypertensive pregnant women and could be used to identify foetuses at risk of morbidity.