1. Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany
2. Department of Obstetrics and Gynecology, Medical University Graz, Austria
3. Department of Obstetrics, University Hospital Zürich, Zürich, Switzerland
4. Obstetrics, Luzerner Kantonsspital, Lucerne, Switzerland
5. AWMF-Institut für Medizinisches Wissensmanagement (AWMF-IMWi), University of Marburg, Germany
6. Department of Obstetrics and Fetal Medicine, University Hospital Hamburg-Eppendorf, Hamburg, Germany