| Affiliation: | 1. Department of Obstetrics, Rigshospitalet Copenhagen University Hospital, Copenhagen, Denmark;2. Department of Obstetrics and Gynaecology, Helsinki University Central Hospital, Helsinki, Finland;3. Department of Gynaecology and Paediatrics, Helsinki University Central Hospital, Helsinki, Finland;4. Department of Gynaecology and Obstetrics, Hyvink?? Hospital, Helsinki and Uusimaa district, Finland;5. THL National Institute for Health and Welfare, Helsinki, Finland;6. Department of Public Health Sciences, Karolinska institute, Stockholm, Sweden;7. Clinitec, Karolinska Institute/Department of Gynaecology and Obstetrics, Karolinska University Hospital, Stockholm, Sweden;8. Department of Evaluation and Analysis, Epidemiology and Methodological Support Unit, National Board of Health and Welfare, Stockholm, Sweden;9. Department of Obstetrics and Gynaecology, Institution of Clinical Sciences, University of Lund, Lund, Sweden;10. Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway;11. Medical Birth Register of Norway, Norwegian Institute of Public Health, Bergen, Norway;12. Department of Obstetrics and Gynaecology, Haukeland University Hospital/University of Bergen, Bergen, Norway;13. Department of Obstetrics and Gynaecology, Landspitali University Hospital, Reykjavik, Iceland;14. Department of Obstetrics and Gynaecology, Holb?k University Hospital, Holb?k, Denmark |
