1. Department of Obstetrics and Gynecology, Akershus University Hospital, Lørenskog, Norway
2. Oslo Centre for Biostatistics and Epidemiology, University of Oslo and Oslo University Hospital, Oslo, Norway
3. Department of Mammography Screening, Cancer Registry of Norway, Oslo, Norway
4. Department of Life Sciences and Health, Faculty of Health Science, Oslo Metropolitan University, Oslo, Norway
5. Institute of Clinical Medicine, Campus Ahus, University of Oslo, Lørenskog, Norway