1. Department of Obstetrics and Gynaecology, University of Düsseldorf, Düsseldorf, Germany
2. Institute of Pathology, Heinrich-Heine University and University Hospital of Düsseldorf, Düsseldorf, Germany
3. Institute of Pathology, Cytology and Molecular Pathology, St. Vincenz Hospital, Limburg, Germany
4. Institute of Pathology, Cytology and Molecular Pathology, Bergisch Gladbach, Germany
5. Department of Obstetrics and Gynaecology, University Hospital Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
6. Medical Faculty, University of Düsseldorf, Düsseldorf, Germany