1. Department of Obstetrics and Gynecology, Cantonal Hospital of Schaffhausen, 8208 Schaffhausen, Switzerland
2. 2nd University Department in Obstetrics and Gynecology, Hippokratio General Hospital, School of Medicine, Aristotle University of Thessaloniki, 54643 Thessaloniki, Greece
3. Laboratory of Histology and Embryology, School of Medicine, Aristotle University of Thessaloniki, 54643 Thessaloniki, Greece
4. 1st University Department in Obstetrics and Gynaecology, Papageorgiou General Hospital, School of Medicine, Aristotle University of Thessaloniki, 54643 Thessaloniki, Greece