1. Department of Obstetrics and Gynecology; Helsinki University Hospital; University of Helsinki; Helsinki Finland
2. Administration; Hyvinkää Hospital; University of Helsinki; Helsinki Finland
3. Department of Obstetrics and Gynecology; Tampere University Hospital; University of Tampere; Tampere Finland
4. Department of Obstetrics and Gynecology; Oulu University Hospital; University of Oulu; Oulu Finland
5. Department of Obstetrics and Gynecology; Turku University Hospital; University of Turku; Turku
6. Department of Obstetrics and Gynecology; Kuopio University Hospital; University of Eastern Finland; Kuopio Finland
7. THL National Institute for Health and Welfare; Helsinki Finland
8. Nordic School of Public Health; Gothenburg Sweden