: Pain modulation is very important after operation, particularly for women who undergo caesarean section. A pain-free postoperative period is essential following a caesarean section so new mothers may care for and bond with their neonates. The consequences of the improper pain management which raise the healthcare costs and prolong the recovery process. Intrathecal adjuvants are often administered during this procedure to provide significant analgesia, but they may also have bothersome side effects. Intrathecal midazolam and magnesium sulfate produces effective postoperative analgesia with no significant side effects.

Objectives: This prospective, randomized, double-blind study was designed to compare the analgesic efficacy and safety of intrathecal midazolam vs. Magnesium sulfate vs plain bupivacaine as an adjunct to bupivacaine in pregnancy patients scheduled for elective caesarean section.

The patients were randomly allocated using a computer-generated randomization list to one of three groups that contained 50 parturients each via www.randomization.com.

Group C (control group): 10 mg hyperbaric bupivacaine 0.5% (2 ml) + 100γ morphine (1ml) + 2.5 γ sufentanil (0.5ml) + 1 ml physiological saline.

Group Mg (magnesium sulfate group): 10 mg hyperbaric Bupivacaine 0.5% (2 ml) + 100γ Morphine (1ml) + 2.5 γ sufentanil (0.5ml) + 100 mg MgSO4 (1 ml).

Group MDZ (midazolam group): 10 mg hyperbaric Bupivacaine 0.5% (2 ml) + 100γ Morphine (1ml) + 2.5 γ Sufentanil (0.5ml) + 2mg Midazolam (0.4 + 0.6cc physiological saline (1 ml)).

The parturients as well as the anesthetist who evaluated the protocol did not know the nature of the adjuvant injected in spinal anesthesia. The presented syringe contained one of the two adjuvants or the physiological serum in the same volume and of the same appearance. It was prepared by an anesthesist who was not included in the analysis of the study and was presented anonymously to the anesthetist in charge of the patient. A postoperative monitoring (PO) was performed during the first 24 hours in the intensive care unit by the anesthesist who did not know the nature of the injected adjuvant. All patients were kept nil per os for six hours prior to surgery.

Inclusion Criteria:

• a mono fetal pregnancy, term> 35 week, planned caesarean section under spinal anesthesia, six-hour fasting, and the American Society of Anesthesiologists (ASA) physical status I or II.

Exclusion Criteria:

• contraindication for intrathecal injection, known allergies to midazolam, other benzodiazepines, magnesium sulfate, caesarean section in extreme urgency, preeclamptic parturient, foetal death in utero, premature delivery (<32SA), anomaly of the placentation, any significant cardiovascular or hepatorenal diseases, a history of seizures or convulsive neurological disease, an altered coagulation profile. Exclusion criteria: failure of spinal anesthesia, conversion into general anesthesia, anesthetic or surgical perioperative incident requiring resuscitation, traumatic puncture, occurrence of serious complication of spinal anesthesia, loss of blindness or randomization of patients.