1. Harris Birthright Center for Fetal Medicine; King's College Hospital; London UK
2. Institute of Health Research; University of Exeter; Exeter UK
3. Chinese University of Hong Kong; Hong Kong China
4. Homerton University Hospital; London UK
5. Ospedale Maggiore Policlinico; Milan Italy
6. Centre Hospitalier Universitaire Brugmann; Université Libre de Bruxelles; Brussels Belgium
7. Medway Maritime Hospital; Gillingham UK
8. Lewisham University Hospital; London UK
9. North Middlesex University Hospital; London UK
10. Hospital Clínico Universitario Virgen de la Arrixaca; Murcia Spain
11. Attikon University Hospital; Athens Greece
12. Hospital Universitario San Cecilio; Granada Spain
13. Hospiten Group; Tenerife Canary Islands Spain