1. Department of Gynecology and Obstetrics, Medical Faculty, University of Cologne, Germany
2. Department of Gynecology and Obstetrics, GFO Clinic Rhein-Berg; Vinzenz-Pallotti-Hospital, Bergisch Gladbach-Bensberg, Germany
3. Institute of Medical Statistics and Computational Biology, University of Cologne, Germany
4. Department of Nuclear Medicine, University of Cologne, Germany
5. Department of Gynecology and Obstetrics, Heilig-Geist-Krankenhaus, Cologne, Germany