1. Center for Fetal Medicine, Pregnancy and Ultrasound, Department of Obstetrics Copenhagen University Hospital, Rigshospitalet Copenhagen Denmark
2. Department of Clinical Medicine University of Copenhagen Copenhagen Denmark
3. Institute of Health Research University of Exeter Exeter UK
4. Ultrasound Clinic BovenMaas Rotterdam The Netherlands
5. Harris Birthright Research Centre for Fetal Medicine, King's College Hospital London UK