In this prospective double blind clinical trial, 150 pregnant women aged 18-40 years old with ASA class 1&2 candidates for cesarean section under spinal anesthesia in Fatemie Hospital are randomly divided into three groups in 5 random block. Exclusion criteria: high risk pregnancy; multiple pregnancy; emergency cesarean section; pre-eclampsia & eclampsia; cardiovascular disease; respiratory disease; psychiatric disease; thyroid disease; diabetes melitus; long history of corticosteroids administration; hypertension; peptic ulcer; need to get blood products; temperature >38 c and contraindication of spinal anesthesia. After spinal anesthesia and neonate delivery patients received 3cc hydrocortisone (2 mg/kg, "A" group) or 3cc ketamine (0.5 mg/kg, "B" group) or 3cc normal saline (%0.9, "C" group) intravenously in 10-15 S duration after umbilical cord clamping. In all patients systolic and diastolic pressure, mean arterial pressure, heart rate, oxygen saturation level, body temperature and sedation score were recorded before anesthesia and then every minute for 5 minute, every 5 minutes for 15 minute, every 10 minutes until the end of surgery. Also, hallucination, nausea and vomiting, incidence and intensity of shivering and using amount of pethidine and ephedrine were recorded in questionnaire.