1. National Public Health Organization of Greece, Department of Obstetrics and Gynecology, Tzaneio Hospital, 18536 Piraeus, Greece
2. 3rd Department of Obstetrics and Gynecology, National and Kapodistrian University of Athens Medical School, Attikon Hospital, 12462 Athens, Greece
3. Department of Obstetrics and Gynecology, Mitera Hospital, 71202 Heraklion, Greece
4. Department of Obstetrics and Gynecology, Democritus University of Thrace Medical School, 68100 Alexandroupolis, Greece
5. Department of Obstetrics and Gynecology, Alexandra Maternity Hospital, 11528 Athens, Greece