1. Vascular Biology Research Centre, Molecular and Clinical Sciences Research InstituteSt George's University of London London UK
2. Fetal Medicine Unit, Department of Obstetrics and GynaecologySt George's University Hospitals NHS Foundation Trust, University of London London UK
3. Balliol CollegeUniversity of Oxford Oxford UK
4. Nuffield Department of Primary Care Health SciencesUniversity of Oxford Oxford UK
5. Department of Obstetrics and Gynecology, Academic Medical Center AmsterdamUniversity of Amsterdam Amsterdam The Netherlands
6. Twin and Multiple Births Association (TAMBA) Aldershot UK
7. The Johns Hopkins Center for Fetal Therapy Baltimore MD USA
8. Department of Obstetrics and GynecologyUniversity Hospitals of KU Leuven Leuven Belgium
9. Barcelona Center for Maternal‐Fetal and Neonatal Medicine, Hospital Clínic and Hospital Sant Joan de DeuUniversitat de Barcelona Barcelona Spain
10. Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) Barcelona Spain
11. Centre for Biomedical Research on Rare Diseases (CIBER‐ER) Barcelona Spain
12. Department of Obstetrics and Fetal MedicineUniversity Medical Center Hamburg‐Eppendorf Hamburg Germany
13. Department of PaediatricsLeiden University Medical Center Leiden The Netherlands
14. Division of Fetal Medicine, Department of ObstetricsLeiden University Medical Center Leiden The Netherlands
15. Department of Obstetrics and Gynecology, University Medical Center GroningenUniversity of Groningen Groningen The Netherlands