1. Norwegian National Advisory Unit on Women's Health; Oslo University Hospital; Oslo Norway
2. Department of Obstetrics; Drammen Hospital; Drammen Norway
3. Department of Obstetrics; Rikshospitalet Oslo University Hospital; Oslo Norway
4. Department of Obstetrics and Gynecology; University Hospital of North Norway; Tromsø Norway
5. Institute of Clinical Medicine; The Arctic University of Norway; Tromsø Norway
6. Institute of Clinical Medicine; University of Oslo; Oslo Norway