1. Department of Obstetrics and Gynaecology; University of Helsinki and Helsinki University Hospital; Helsinki Finland
2. Information Services Department; THL National Institute for Health and Welfare; Helsinki Finland
3. Department of Neurobiology; Care Sciences and Society, Division of Family Medicine, Karolinska Institute; Stockholm Sweden
4. Finnish Cancer Registry, Institute for Statistical and Epidemiological Cancer Research; Helsinki Finland
5. Faculty of Social Sciences, University of Tampere; Finland