1. Department of Obstetrics and Gynecology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
2. Department of Obstetrics and Gynecology, Sankt Elisabeth Hospital, Gütersloh, Germany
3. Department of Anatomy and Cell Biology, Medical Faculty of Saarland University, Homburg, Germany
4. Department of Obstetrics and Gynecology, MHK St. Elisabeth, Neuwied, Germany