1. University Hospital for Gynecology, Pius Hospital, University Medicine Oldenburg, Carl von Ossietzky University, 26121 Oldenburg, Germany
2. University Hospital for Gynecology and Obstetrics, University Hospital Frankfurt, 60596 Frankfurt, Germany
3. Clinic of Gynecology, Obstetrics, Oncology, and Senology, Bethesda Hospital, 47053 Duisburg, Germany