1. Division of Obstetrics and Gynecology, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
2. Division of Anaesthesia and Intensive Care, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
3. Department of Anaesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden
4. Division of Mathematical Statistics, Centre for Mathematical Sciences, Lund University, Lund, Sweden
5. Department of Energy Sciences, Faculty of Engineering, Lund University, Lund, Sweden
6. Department of Obstetrics and Gynecology, Skåne University Hospital, Lund/Malmö, Sweden