1. Women's Health and Perinatology Research Group, Department of Clinical Medicine, Faculty of Health Sciences, University of Tromsø and Department of Obstetrics and Gynecology University Hospital of North Norway Tromsø Norway
2. Department of Clinical Science, Intervention & Technology, Karolinska Institutet and Center for Fetal Medicine Karolinska University Hospital Stockholm Sweden
3. Department of Obstetrics and Gynecology Haukeland University Hospital Bergen Norway
4. Department of Clinical Science University of Bergen Bergen Norway