<prompt> Increased acidosis and hypoxaemia is seen inNormal doppler wave formIncreased fetal diastolic flow in the middle cerebral artery with absent diastolic flow in the aortaPresence of the notch in the uterine arteryAbsent umbilical artery  <response>: Increased fetal diastolic flow in the middle cerebral artery with absent diastolic flow in the aorta648- DDoppler - direction as well as velocity of blood flow can be measured by doppler ultrasound. Reduced diastolic flow indicates high resistance in the downstream vessel and low tissue perfusion. Presence ofnotch in the early diastolic waveform also indicates high resistance in the downstream vessel and low tissue perfusion. Presence of notch in uterine artery when confirmed bilaterally at 24 weeks indicates the possible development of preclampsia and fetal growth restriction Absent end diastolic flow in the umbilical artery was associated with 16 fetal death rate and reversed diastolic flow with 50 fetal death rates. Increased fetal diastolic flow in the middle cerebral artery centralization of flow with absent diastolic flow in the aorta implies fetal acidemia Abnormal venous waveforms ductus venosus, IVC indicates fetal cardiac dysfunction failureSingle umbilical artery - It is more common in twins and in babies bom of diabetic mothers or in polyhydramnios. It is frequently associated with congenital malformation of the fetus 10-20. Renal and genital anomalies, Trisomy 18 are common, 228-D There is increased chances of abortion, prematurity, IUGR, and increased perinatal mortality. 