Fetal Aortic-cerebral Doppler Resistance Index Ratio: An Indicator of Physiologic Blood Flow Distribution

Identical hemodynamic impedance and constant ratio of the fetal descending aorta and middle cerebral artery of uncomplicated pregnancies at term. Fetal aortic-cerebral Doppler resistance index ratio: An indicator of physiologic blood flow distribution. Objective: To interpret the physiologic fetal arterial blood flow distribution by relating the vascular impedance of the fetal descending aorta (DA) and middle cerebral artery (MCA) and to establish the reference ranges for the aortic-cerebral Doppler resistance index ratio