1. Reproductive Medicine Unit, New EGA, UCLH, Euston Road, London NW1 2BU, UK
2. 15 Rue Guilleminot 75014 Paris, France
3. National ART Register, National Centre for Epidemiology, Surveillance and Health Promotion Istituto Superiore di Sanità Viale Regina Elena, 299, 00161 Roma, Italy
4. Reproductive Medicine Center, Altonaer Str. 59, D-20357 Hamburg, Germany
5. SISMER Via Mazzini 12, 40138 Bologna, Italy
6. HM Fertility Center Montepríncipe Boadilla del Monte 28660, Madrid, Spain
7. European Society of Human Reproduction and Embryology, Meerstraat 60, B-1852 Grimbergen, Belgium