1. Assisted Reproduction Unit, 3rd Department of Obstetrics and Gynecology, University of Athens, Attikon Hospital, Rimini 1, Chaidari, 12642 Athens, Greece
2. 3rd Department of Obstetrics and Gynecology, University of Athens, Attikon Hospital, Rimini 1, Chaidari, 12642 Athens, Greece
3. School of Clinical Sciences, University of Bristol, Level D, St Michael’s Hospital, Bristol BS2 8EG, UK
4. 2nd Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, Vasilissis Sofias 76, 11528 Athens, Greece