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