1. Obstetrics and Gynecology, University of Ulm, Germany
2. Frankfurt, Center for Ultrasound and Prenatal Medicine, Frankfurt/Main, Germany
3. Gynecology and Obstetrics, Practice of prenatal medicine, Weimar, Germany
4. Prof. Tutschek, Prenatal Zurich, Zürich, Switzerland
5. Department of Obstetrics and Gynaecology, University of Tuebingen, Germany
6. Berlin, Prenatal Diagnosis and Human Genetics, Berlin, Germany
7. Leipzig, Center of Prenatal Medicine, Leipzig, Germany
8. Department of Obstetrics and Gynecology, Medical University Graz, Austria
9. Department of Gynecology and Obstetrics, Diakonieklinik, Schwäbisch Hall, Germany
10. Obst Gyn, Practice of prenatal medicine Erfurt, Germany
11. Obstetrics, Charité University Hospital Berlin – Virchow Hospital Campus, Berlin, Germany
12. Department of prenatal medicine and gynecologic ultrasound, University Hospital Basel, Switzerland
13. Department of Obstetrics and Gynecology, Medical University of Vienna, Austria
14. Department of Obstetrics and Gynaecology, University of Tübingen, Tübingen, Germany