1. Department of Obstetrics and Gynecology, University of Saarland, Homburg, Germany;
2. Department of Obstetrics and Gynecology, Cleveland Clinic – Akron General, Akron, OH, USA;
3. Department of Obstetrics, Gynecology and Reproductive Medicine, Homburg, Germany;
4. Department of Gynecology and Obstetrics, St Joseph’s Hospital Berlin Tempelhof, Berlin, Germany