Manon C Stam-Slob1, Cornelis B Lambalk2, Marcel A van de Ree3. 1. Department of Internal Medicine, Diakonessenhuis Utrecht, Postbus 80250 3508TG, Utrecht, Netherlands University Medical Centre Utrecht, Utrecht, Netherlands mslob@umcutrecht.nl. 2. Department of Obstetrics and Gynaecology, VU Medical Centre, Postbus 7057 1007 MB, Amsterdam, Netherlands. 3. Department of Internal Medicine, Diakonessenhuis Utrecht, Postbus 80250 3508TG, Utrecht, Netherlands.