1. Department of Obstetrics and Gynecology, Hyvinkää Hospital, Hyvinkää, Finland;
2. Department of Obstetrics and Gynecology, Turku University Hospital, Turku, Finland;
3. University of Turku, Turku, Finland;
4. School of Medicine, University of Tampere, University of Tampere, Finland;
5. Department of Obstetrics and Gynecology, Tampere University Hospital, Tampere, Finland;
6. Department of Obstetrics and Gynecology, Helsinki University Hospital, Helsinki, Finland;
7. University of Helsinki, Helsinki, Finland;
8. School of Health Sciences, University of Tampere, University of Tampere, Tampere, Finland;
9. Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research, Helsinki, Finland