1 First Department of Obstetrics and Gynecology, Maternal-Fetal Medicine Unit, National and Kapodistrian University of Athens, Alexandra Maternity Hospital Athens, Greece.
2 Center of Mother and Child, Philipps University of Marburg, Baldingerstrasse, 35032 Marburg, Germany.
3 Clara Angela Foundation, Berlin, Germany.
4 Preterm Birth Prevention Clinic, High-Risk Pregnancy Unit, Maternal-Foetal Medicine, Department of Obstetrics and Gynaecology, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute (VHIR), Universitat Autònoma de Barcelona (UAB), Barcelona., Spain.