1. Zentrallabor, Kantonsspital Graubünden, Chur, Switzerland;
2. Labormedizinisches Zentrum Dr. Risch, Department of Clinical Chemistry, Vaduz, Liechtenstein;
3. Department of Obstetrics and Gynecology, Inselspital, University of Bern, Bern, Switzerland;
4. Department of Internal Medicine, Sonnenhofspital, Bern, Switzerland;
5. Institute of Laboratory Medicine, Philipps University Marburg, Marburg, Germany;
6. Center of Laboratory Medicine, University Institut of Clinical Chemistry, University of Bern, Bern, Switzerland