1. Fetal Medicine Unit, St George's University Hospitals NHS Foundation TrustUniversity of London London UK
2. Vascular Biology Research Centre, Molecular and Clinical Sciences Research InstituteSt George's University of London London UK
3. Department of Obstetrics and Gynecology, University Medical Center GroningenUniversity of Groningen Groningen The Netherlands
4. Department of Health Sciences, Community and Occupational Medicine, University Medical Center GroningenUniversity of Groningen Groningen The Netherlands
5. Department of Obstetrics and Gynecology, Academic Medical Center AmsterdamUniversity of Amsterdam Amsterdam The Netherlands
6. Hospital Clinic de Barcelona Barcelona Spain
7. University of Toronto Toronto Ontario Canada
8. Institute for Women's HealthUniversity College London London UK
9. Institute of Child HealthUniversity College London London UK
10. Center for Epidemiology and Biostatistics Paris France
11. Center for Fetal Therapy, Department of Gynecology & ObstetricsJohns Hopkins School of Medicine Baltimore MD USA