1. Department of Clinical Epidemiology and Biostatistics, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
2. MRC Epidemiology Resource Centre, University of Southampton, Southampton, U.K.
3. Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
4. Department of Endocrinology and Metabolic Medicine, Imperial College London, London, U.K.
5. Department of Obstetrics and Gynaecology, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands