1. Harris Birthright Centre 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. Medway Maritime Hospital; Gillingham UK
5. Homerton University Hospital; London UK
6. North Middlesex University Hospital; London UK
7. Centre Hospitalier Universitaire Brugmann; Université Libre de Bruxelles; Brussels Belgium
8. Hospital Universitario San Cecilio; Granada Spain
9. Hospital Clínico Universitario Virgen de la Arrixaca; Murcia Spain
10. Attikon University Hospital; Athens Greece
11. Ospedale Maggiore Policlinico; Milan Italy
12. Hospiten Group; Tenerife Canary Islands Spain
13. Southend University Hospital; Essex UK