Analgesia after cesarean section is still not satisfactory for many women. Even if pain reduction is sufficient with the technique of intrathecal morphine injection, side effects such as nausea and pruritus are common.

Since several years, an alternative technique has been studied, the "transversus abdominis plane (TAP)"-block. Here a local anesthetic is injected in the abdominal wall muscles, and this has been shown to give a similar analgesic effect compared to intrathecal morphine, with potentially less side effects.

With this study, we want to evaluate if the TAP-block yields indeed less side effects when compared with intrathecal morphine.

The study will be a prospective study with the patients randomized to either a group with intrathecal morphine or a group with TAP-block.

Inclusion Criteria:

Subjects must satisfy all of the following criteria to be enrolled into the study:

• American Society of Anesthesiology (ASA) physical status less than 3 Able to read and understand the information sheet and to sign and date the consent form
• Scheduled for elective C-section planned with spinal anaesthesia
• Age>18

Exclusion Criteria:

Potential subjects who meet any of the following criteria will be excluded from participating in the study:

• Complicated pregnancy defined as having preeclampsia or placenta accreta, increta and percreta.
• Drug addiction.
• Contraindication to spinal anaesthesia (history of clotting disorders, septicemia, local infection at the injection site, spinal malformation, elevated intracranial pressure)
• Contraindication to TAP block (skin infection, abdominal wall muscle defect such as hernia and previous abdominal wall mesh).
• BMI>40 kg/m2
• Weight less than 50 kg the day of the C-section.
• Height less than 150 cm or more than 175 cm.
• Allergy/contraindication to any medication used in the study.
• Previous median abdominal incision. Necessity to perform the C-section urgently before the scheduled date (with less than 24h preparation time).

pharmacy providing identical sets of study drugs and placebo, computerized random sequence generation, sequence held by the pharmacy until study completion