1 Deparment of Obstetrics and Gynecology, St. Olav's University Hospital, Trondheim, Norway.
2 Department of Reproductive Medicine, St Mary's Hospital, Central Manchester NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK.
3 Department of Obstetrics and Gynaecology, IVF Laboratory, Maastricht University Medical Center, Maastricht, The Netherlands.
4 Embryology, IVF and Reproductive Genetics Group, Institute for Women's Health, University College London, London, UK.
5 Reproductive Medicine, Sahlgrenska University Hospital, Göteborg, Sweden.
6 SISMER, Reproductive Medicine Unit, Bologna, Italy.
7 Reproductive Medicine, Ghent University Hospital, Gent, Belgium.
8 Reproductive Medicine Service, Hospital Universitari Dexeus, Barcelona, Spain.