Antepartum foetal surveillance is the cornerstone of management aimed at reducing maternal and perinatal mortality and morbidity. Doppler velocimetry of the uteroplacental and fetoplacental circulation can be used to further evaluation in such complications of pregnancy as foetal growth restriction. Aims and Objectives: To study the Systolic / Diastolic ratio (S/D ratio), pulsatility index (PI) and resistance index (RI) of the umbilical artery and middle cerebral arteries in high-risk pregnancies. The ratio of middle cerebral to umbilical artery blood velocity in high-risk pregnancies. Also, to evaluate the role of these blood flow indices in the prediction of adverse foetal outcome. Materials and Methods: This prospective study included 90 pregnant patients with high-risk factors in the III trimester after 30 weeks who got admitted to Department of OBG, Mamata Academy of Medical Sciences, Bachupally, Hyderabad, from October 2018 to November 2019. Results: Total number of 90 high-risk cases were studied. In these 46 cases had intrauterine growth retardation. A ratio of Middle cerebral artery RI / Umbilical artery RI shows more sensitivity and specificity than MCA RI (60% Vs 28%) and (75% Vs 67%) respectively. It was also more sensitive and specific than Umbilical artery RI (61% Vs 50%) and (75% Vs &72%) respectively. However, the most sensitive parameter was Middle Cerebral Artery PI (95%), and the most specific parameter was Umbilical artery PI (81%). Conclusion: It has been proved that Doppler technology has a significant impact on our ability to assess the physiological status of the foetus. It can help in evaluating the changes in the foetal circulation. This study suggests that ..................