1. Department of Prenatal Cardiology, Polish Mother’s Memorial Hospital Research Institute, Lodz , Poland
2. Faculty of Health Sciences, The State School of Higher Professional Education in Płock , Poland
3. University of Giessen, Ludwigstraße 23, 35390 Gießen , Germany
4. University of Marburg, Biegenstraße 10, 35037 Marburg , Germany
5. Department of Obstetrics and Gynecology, Università Roma Tor Vergata, Ospedela Fatebenefratelli Isola Tiberina, Rome , Italy
6. Division of Pediatric Cardiology, Department of Pediatrics, David Geffen School of Medicine, Los Angeles, California , USA
7. Thomas Jefferson University and Hospitals, Philadelphia, Pennsylvania , USA
8. Department of Obstetrics and Gynecology, Kaplan Medical Center, 76100 Rehovot and the Hadassah-Hebrew University School of Medicine, Jerusalem , Israel
9. Department of Diagnoses and Prevention Fetal Malformations, Medical University of Lodz, Lodz , Poland