1. Early pregnancy and Acute Gynaecology Unit, Department of Obstetrics and Gynaecology, Queen Charlotte's and Chelsea Hospital Imperial College London UK
2. Department of Obstetrics and Gynaecology University Hospitals Leuven Leuven Belgium
3. KU Leuven, Department of Development and Regeneration Leuven Belgium
4. Acute Gynecology, Early Pregnancy & Advanced Endoscopic Surgery Unit Sydney Medical School Nepean, University of Sydney Nepean Hospital, Penrith Sydney Australia
5. Fondazione Policlinico Universitario Agostino Gemelli IRCCS, Dipartimento Scienze della Salute della Donna, del Bambino e di Sanità Pubblica Rome Italy
6. Gynaecological Oncology Centre, Department of Obstetrics and Gynecology, First Faculty of Medicine Charles University and General University Hospital in Prague Prague Czech Republic
7. Centre d'Échographie de l'Odéon Paris France