Background: Hypotension following spinal anaesthesia is a common complication with an incidence ranging from 25-75% among general population and a little higher in women undergoing Caesarean section with more intraoperative and postoperative morbidity. Several techniques and protocols have been used for the prevention of this neuraxial hypotension with varying degree of success. Aim of the study: to compare the effect of pre-load colloid and co-load crystalloid fluid administration on maternal blood pressure during spinal anesthesia for Cesarean delivery. Patients and Methods: This Prospective, randomized, comparative clinical trial included fifty pregnant women whounderwent elective cesarean section under spinal anesthesia, aging 25-35 years old. The patients were divided into two equal groups, Pre-load group:received rapid infusion of a colloid solution 10 ml/kg of Voluven [6% Hydroxyethyl starch 130/0.4 in 0.9 Sodium Chloride] over 20 minutes before initiation of spinal anaesthesia.Co-load group: patients received a crystalloid solution 20ml/kg of lactated Ringer's solution at the beginning of the procedure of spinal anaesthesia over 20 minutes. Results: There were no statistically significant differences between both groups regarding systolic, diastolic and mean blood pressure, as well as Oxygen saturation and heart rate at all times. Side effects (nausea and vomiting) and blood loss were insignificantly less in the co-load group compared to pre-load group. There was no statistically significant difference between both groups in Apgar score at 1min. and at 5min. There were no statistically significant differences between groups in the need for ephedrine and total dose administered. Conclusion: There is no significant difference between both groups in prevention of spinal anesthesia- induced hypotension in elective cesarean cases. Valuable time need not be wasted in preloading parturient as preloading alone is not effective for the prevention of maternal hypotension during a cesarean section under
spinal anesthesia.