1. Frauenklinik der Technischen Universität München (TUM), Klinikum Rechts der Isar, Ismaninger Str., 22 81675 Muenchen, Germany
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, University of British Columbia and Centre for Menstrual Cycle and Ovulation Research (CeMCOR), 2775 Laurel Street, Vancouver, BC, V5Z 1M9, Canada