This pilot study aims to investigate the effects of a brief computerized intervention (the computer game "Tetris") on intrusive memories and other posttraumatic stress symptoms following an emergency cesarean section. Patients who have undergone an emergency cesarian section will be randomly allocated to either the brief computerized intervention or usual care within the first 6 hours following the operation. Participants will be followed up at one week and one month. It is predicted that participants given the brief computerized intervention will develop fewer intrusive memories and less severe clinical symptoms than those who are not. This will inform the potential future development of a simple computerized intervention to prevent distressing psychological symptoms after a traumatic event such as an emergency cesarean section.