1. 2nd University Clinic of Obstetrics and Gynaecology, Aristotle University of Thessaloniki, Thessaloniki, Greece;
2. Hematological Laboratory, 2nd Department of Internal Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece;
3. University of Zurich, Clinic of Obstetrics, Feto Maternal Haematology University of Zurich, Zurich, Switzerland