1. Department of Obstetrics and Gynecology, Hospital de la Santa Creu i Sant Pau, 08025 Barcelona, Spain
2. Institute of Biomedical Research Sant Pau (IIB SANT PAU), 08041 Barcelona, Spain
3. Department of Obstetrics and Gynecology, Hospital Universitari i Politècnic La Fe, 46026 València, Spain
4. Department of Obstetrics and Gynecology, Hospital General Universitari de Castelló, 12004 Castelló, Spain
5. Department of Obstetrics, Gynecology and Reproduction, Hospital Universitari Dexeus, 08028 Barcelona, Spain
6. Centro Integrato di Procreazione Medicalmente Assistita (PMA) e Diagnostica Ostetrico-Ginecologica, Azienda Ospedaliero Universitaria-Policlinico Duilio Casula, 09042 Monserrato, Italy
7. Department of Obstetrics and Gynecology, Università degli Studi di Cagliari, 09043 Monserrato, Italy
8. Department of Obstetrics and Gynecology, School of Medicine, Universidad de Navarra, 31009 Pamplona, Spain