1. Institute for Social Medicine and Epidemiology, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
2. Department of Obstetrics and Gynecology, Ernst von Bergmann Clinic, Charlottenstraße 72, 14467 Potsdam, Germany
3. Department of Gynecology and Obstetrics, Hospital Dueren gem. GmbH, Roonstraße 30, 52351 Dueren, Germany
4. Department of Obstetrics and Gynecology, University Hospital of Schleswig-Holstein, Campus Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
5. Institute for Cancer Epidemiology e.V., University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany