A Ugwumadu1, P Steer2, B Parer3, B Carbonne4, C Vayssiere5, G Maso6, S Arulkumaran1. 1. Department of Obstetrics & Gynaecology, St George's University Hospital NHS Foundation Trust, London, UK. 2. Academic Department of Obstetrics and Gynaecology, Chelsea and Westminster Hospital, London, UK. 3. Department of Obstetrics and Gynecology and Reproductive Sciences, University of California, San Francisco, CA, USA. 4. Service de Gynécologie-Obstétrique, Centre Hospitalier Princesse Grace, Monaco. 5. Hôpital Joseph-Ducuing, Toulouse, France. 6. Department of Obstetrics and Gynaecology, Institute for Maternal and Child Health, IRCCS- Burlo Garofolo, Trieste, Italy.