1 Department of Obstetrics and Gynecology, University Hospital Brugmann, Université Libre de Bruxelles, Brussels, Belgium.
2 Obstetrics and Gynecology Department, Hospital Universitario de Torrejón, Torrejón de Ardoz, Universidad Francisco de Vitoria, Madrid, Spain.
3 Department of Obstetrics and Gynecology, Antoine-Béclère Hospital, Assistance Publique-Hôpitaux de Paris (AP-HP), Université Paris-Sud, Clamart, France.
4 Division of Obstetrics and Gynecology, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
5 Tuebingen University Hospital, Obstetrics and Gynaecology, Tuebingen, Germany.
6 Center of Fetal Medicine, Department of Obstetrics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
7 Department of Obstetrics & Gynaecology, Amsterdam University Medical Centers, Amsterdam, The Netherlands.
8 Department of Obstetrics and Gynecology, Centre for Perinatal and Reproductive Medicine, University Hospital, University of Perugia, Perugia, Italy.
9 Fetal Medicine Research Institute, King's College Hospital, London, UK.