1. Department of Gynecology and Obstetrics, Lutheran Hospital Hagen-Haspe, Brusebrinkstraße 20, 58135 Hagen, Germany
2. Department of Urology, Lukas Hospital, Preussenstraße 84, 41464 Neuss, Germany
3. Department of Gynecology and Obstetrics, Cantonal Hospital, Pfaffenholzstraße 4, 8501 Frauenfeld, Switzerland
4. Department of Obstetrics and Gynecology, Medical University of Warsaw, Żwirki i Wigury 61, 02-091 Warsaw, Poland