1. Second Department of Obstetrics and Gynecology Faculty of Medicine Aristotle University of Thessaloniki Ippokrateio Hospital of Thessaloniki Thessaloniki Greece
2. Third Department of Internal Medicine Papageorgiou General Hospital Aristotle University of Thessaloniki Thessaloniki Greece
3. School of Medicine Department of Hygiene, Epidemiology and Medical Statistics National and Kapodistrian University of Athens Athens Greece