1. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, American University of Beirut Medical Center, Faculty of Medicine and Medical Center, Beirut, Lebanon;
2. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY, USA;
3. Biostatistics Unit, Clinical Research Institute, American University of Beirut Medical Center, Beirut, Lebanon