To demonstrate the superiority of square lumbar block to ropivacaine compared to intrathecal morphine in the efficacy of postoperative analgesia following scheduled caesarean.

Interventional, comparative, randomized, controlled study versus reference therapeutic strategy, in 2 parallel groups, double-blind (patient and evaluator), single-center, aiming to demonstrate the superiority of ropivacaine in square lumbar block versus intrathecal morphine, on the efficacy of post-operative analgesia, following a scheduled caesarean.

Inclusion Criteria:

• Patient to undergo a scheduled caesarean under spinal anesthesia, for the birth of a term baby with a Pfannenstiel-type incision;
• Patient in good health ;
• Patient able to understand the information related to the study, read the information leaflet and agree to sign the consent form.

Exclusion Criteria:

• Pregnancy less than 37 weeks with amenorrhea;
• Multiple pregnancy;
• Fetal pathology known at the time of inclusion;
• Body mass index> 45 kg / m²;
• History of scoliosis or spine surgery;
• History of chronic pain associated with taking opiates, neuropathic pain, neurological pathology;
• Preoperative anemia (blood hemoglobin <9 g / dL);
• Hypersensitivity to ropivacaine or other local anesthetics with amide bond;
• Hypersensitivity to morphine or opioids;