1. Department of Gynaecology and Obstetrics, University of Würzburg, Würzburg, Germany
2. Institute of Medical Biostatistics, Epidemiology and Informatics, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, Germany
3. University Cancer Centre Mainz, Mainz, Germany
4. Department of Gynaecology and Obstetrics, University of Ulm, Ulm, Germany
5. Department of Gynaecology and Obstetrics, Hospital Esslingen, Esslingen, Germany
6. Department of Gynaecology and Obstetrics, Hospital Memmingen, Memmingen, Germany
7. Department of Gynaecology and Obstetrics, Hospital Kempten, Kempten, Germany