1. Department of Obstetrics and Gynecology, Academic Medical Centre, Amsterdam, The Netherlands
2. Department of Clinical Epidemiology, Biostatistics, and Bioinformatics, Academic Medical Centre, Amsterdam, The Netherlands
3. The Robinson Research Institute, School of Medicine, University of Adelaide, The South Australian Health and Medical Research Institute Adelaide, Australia
4. Department of Obstetrics and Gynecology, VU University Medical Centre, Amsterdam, The Netherlands