1 Royal Brompton Hospital, Guy's & St Thomas' NHS Foundation Trust; and Fetal Medicine Unit, St George's University Hospitals NHS Foundation Trust and Cardiovascular Clinical Academic Group, Molecular and Clinical Sciences Research Institute, St George's, University of London, London, UK.
2 Division of Prenatal Medicine & Fetal Therapy, Department of Obstetrics & Gynecology, Justus-Liebig-University Giessen, University Hospital Giessen & Marburg, Giessen, Germany.
3 Center of Prenatal Diagnosis and Human Genetics, Berlin, Germany.
4 Departments of Obstetrics, Gynecology & Reproductive Sciences, and Pediatrics, Yale School of Medicine, New Haven, CT, USA.
5 Children's Hospital Colorado, The Heart Institute, Aurora, CO, USA.
6 Pediatrix Cardiology of Houston and Loma Linda University School of Medicine, Houston, TX, USA.
7 Obstetrical Unit, Shamir Medical Center (formerly Assaf Harofeh Medical Center), Zerifin, Israel; and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
8 Department of Obstetrics and Fetal Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
9 Department of Obstetrics and Gynecology, Baylor College of Medicine and Texas Children's Hospital, Houston, TX, USA.
10 Clinical Pediatrics, UC San Francisco, San Francisco, CA, USA.
11 Fetal Medicine Unit, University of Leicester, Leicester, UK.
12 Obstetrics and Gynecology, Universidad de Chile and Clinica Las Condes, Santiago, Chile.
13 Fetal Medicine and Surgery Unit, IRCCS Istituto G. Gaslini, Genoa, Italy.
14 Obstetrics and Gynecology Unit, IRCCS Istituto G. Gaslini, Genoa, Italy.
15 Image 2 Center, Obstetrics and Gynecologic Department, St Joseph Hospital, Marseille, France.
16 Fetal Heart Program at Children's Hospital of Philadelphia, and Perelman School of Medicine at University of Pennsylvania, Philadelphia, PA, USA.
17 Pränatal Zürich, Zürich, Switzerland; and Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.
18 Department of Gynecology and Obstetrics, Jagiellonian University in Krakow, Krakow, Poland.
19 Department of Obstetrics and Gynecology, Hadassah Medical Center, Mt. Scopus and the Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.