1. Department of Obstetrics and Gynaecology, Fundación Instituto Valenciano de Infertilidad (FIVI), School of Medicine, Valencia University and Instituto Universitario IVI/INCLIVA, Valencia, Spain
2. Instituto Valenciano de Infertilidad (IVI), Barcelona, Spain
3. Department of Obstetrics and Gynaecology, Keio University School of Medicine, Tokyo, Japan