1. Department of Anesthesiology, Oulu University Hospital, Finland,
2. Department of Anesthesiology, Oulu University Hospital, Finland
3. Department of Obstetrics and Gynecology, Oulu University Hospital, Finland
4. Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tromsø and University Hospital of Northern Norway, Tromsø, Norway
5. Department of Surgery, Oulu University Hospital, Finland