Traditionally clinicians and researchers have used heart rate (HR)and BP as surrogate markers of cardiac output during spinal anaesthesia. Managing maternal BP was considered as safe optimization of foetal wellbeing. Recent publications have emphasized that keeping BP at baseline is not an optimal strategy and maintaining CO is superior in maintaining uterine blood flow. In addition the correlation of the foetal compromise in the form of umbilical artery pH and umbilical artery pulsatality index was better related to SV and CO than BP and heart rate. 19 Thus measurement of CO is considered a better approach than BP in optimising oxygen delivery to the foetus.