1. Department of Gynaecology, University Hospital and University Zurich, Zurich 8091, Switzerland
2. Department of Obstetrics and Gynaecology, Cantonal Hospital Aarau, Aarau 5001, Switzerland
3. Department of Obstetrics and Gynaecology, Cantonal Hospital Winterthur, Winterthur 8400, Switzerland
4. Department of Obstetrics and Gynaecology, Triemli Hospital, Zurich 8063, Switzerland
5. Department of Gynaecology, St. Clarapsital, University Basel, Basel 4058, Switzerland
6. Department of Obstetrics, University Hospital Zurich, University of Zurich, Zurich 8091, Switzerland
7. Clinic Arlesheim, Research Department, Arlesheim 4144, Switzerland