1. Department of Obstetrics and Gynecology, Division of Perinatal Medicine, Hacettepe University, Ankara, Turkey
2. Department of Obstetrics and Gynecology, Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece
3. Department of Biostatistics, Hacettepe University, Ankara, Turkey
4. Department of Obstetrics and Gynecology, Universitatea de Medicina si Farmacie Iuliu Hatieganu, Cluj-Napoca, Romania