1. Women’s Health & Perinatal Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway
2. Department of Obstetrics and Gynecology, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
3. Department of Obstetrics and Gynecology, Helsinki University Hospital, Helsinki, Finland
4. Department of Obstetrics and Gynecology, Oulu University Hospital, Oulu, Finland
5. Department of Anesthesiology, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
6. Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
7. Department of Statistics, Oulu University Hospital, Oulu, Finland
8. Department of Obstetrics and Gynecology, Lapland Central Hospital, Finland
9. Department of Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institute, Stockholm, Sweden