1. Department of Reproductive Endocrinology, University Hospital Zurich, Frauenklinikstrasse 10, 8091 Zurich, Switzerland
2. Division of Gynecology and Obstetrics, Inselspital Bern, 3010 Bern, Switzerland
3. Division of Gynecological Endocrinology and Reproductive Medicine, Cantonal Hospital of Lucerne, 6000 Lucerne, Switzerland
4. Department of Gynecology and Obstetrics, Canton Hospital St. Gallen, 9007 St. Gallen, Switzerland
5. Department of Gynecology and Obstetrics, Triemli Hospital Zurich, 8063 Zurich, Switzerland
6. Department of Gynecology and Obstetrics, Canton Hospital Schaffhausen, 8208 Schaffhausen, Switzerland