1. Department of Clinical Chemistry , Erasmus MC, University Medical Center , Rotterdam , The Netherlands
2. Department of Obstetrics and Gynecology , Erasmus MC, University Medical Center , Rotterdam , The Netherlands
3. Department of Internal Medicine, Division of Endocrinology , Erasmus MC, University Medical Center , Rotterdam , The Netherlands
4. Obesity Center CGG , Erasmus MC, University Medical Center , Rotterdam , The Netherlands