1. Department of Obstetrics and Gynecology University Medical Center Groningen, University of Groningen Groningen The Netherlands
2. Department of Obstetrics and Gynecology Amsterdam University Medical Center Amsterdam The Netherlands
3. Molecular and Clinical Sciences Research Institute St George's University of London London UK
4. Fetal Medicine Unit, Department of Obstetrics and Gynaecology St George's University Hospitals NHS Foundation Trust London UK
5. Department of Epidemiology University Medical Center Groningen, University of Groningen Groningen The Netherlands
6. Department of Obstetrics and Gynecology Leiden University Medical Center Leiden The Netherlands
7. Department of Obstetrics and Gynecology Ikazia Hospital Rotterdam The Netherlands
8. Amsterdam Reproduction and Development Research Institute Amsterdam The Netherlands