1. Department of Obstetrics and Gynaecology; University of Tübingen; Tübingen Germany
2. Fetal Medicine Foundation USA; Dayton OH USA
3. Division of Maternal Fetal Medicine; Wright State University; Dayton OH USA
4. Department of Obstetrics and Gynaecology; University of Bonn; Bonn Germany
5. Department of Obstetrics and Gynaecology; University of Cologne; Cologne Germany