1. Division of Reproductive Endocrinology and Infertility, Obstetrics and Gynecology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
2. First Department of Obstetrics and Gynecology, Alexandra Hospital, Medical School of the National and Kapodistrian University of Athens, 11528 Athens, Greece
3. Third Department of Obstetrics and Gynecology, University General Hospital “ATTIKON”, Medical School of the National and Kapodistrian University of Athens, 12462 Athens, Greece
4. Department of Obstetrics and Gynecology, Royal Cornwall Hospital, Treliske, Truro TR1 3LQ, UK
5. Department of Obstetrics and Gynecology, Medical School of the University of Ioannina, 45110 Ioannina, Greece