Efficacy and Safety of Intrathecal Morphine for Postoperative Pain Management Following Planned Caesarean Section

The goal of this clinical trial is to learn if morphine added to the spinal anaesthesia can improve postoperative pain treatment for patients undergoing caesarean section, without increasing the risk of serious adverse events in mother and baby. The main questions it aims to answer are: * Is the treatment effective in preventing postoperative pain? * Is the treatment safe for both mother and baby? Participants will be given a normal spinal anaesthesia with addition of either morphine or sodium chloride (inactive substance). All participants will receive standard postoperative pain treatment, including morphine tablets as needed. Researchers will collect data from the electronic medical record and ask the participants to fill out questionnaires about pain levels and possible side effects.