1. Faculty of Medicine, University of Cologne, Joseph-Stelzmann-Str. 20, 50931 Cologne, Germany
2. Department of Obstetrics and Gynecology, University of Cologne, Kerpener Str. 34, 50931 Cologne, Germany
3. Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf, Germany
4. Department of Surgery, Helios University Hospital Wuppertal, Heusnerstr. 40, 42283 Wuppertal, Germany
5. Department of Obstetrics and Gynecology, Hospital of the City of Cologne, Neufelder Str. 32, 51067 Cologne, Germany