1Department of Obstetrics and Gynecology, University Hospital of Turku, Finland
2Department of Obstetrics and Gynecology, University Hospital of Helsinki, Finland
3National Research and Development Center for Welfare and Health (STAKES), Helsinki, Finland
4Department of Obstetrics and Gynecology, University Hospital of Oulu, Finland
5Department of Obstetrics and Gynecology, University Hospital of Tampere, Finland
6Department of Obstetrics and Gynecology, University Hospital of Kuopio, Finland