1. Department of Obstetrics and Gynecology, University of Helsinki and Helsinki University Hospital , Haartmaninkatu 8, 00290 Helsinki , Finland
2. Department of Obstetrics and Gynecology, Institute of Clinical Medicine, University of Tartu , 50406 Tartu , Estonia
3. Competence Centre on Health Technologies , 50411 Tartu , Estonia
4. Department of Obstetrics and Gynecology, Research Unit of Clinical Medicine, Medical Research Center, Oulu University Hospital, University of Oulu , 90220 Oulu , Finland
5. Department of Obstetrics and Gynaecology, HFR—Cantonal Hospital of Fribourg and University of Fribourg , 79085 Fribourg , Switzerland
6. Division of Obstetrics and Gynecology, Department of Clinical Science, Intervention and Technology, Karolinska Institutet and Karolinska University Hospital , 14152 Huddinge, Stockholm , Sweden