1. Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA
2. Dipartimento di Scienze Ginecologiche e della Riproduzione Umana, Universita’ di Padova, Italy
3. Department of Obstetrics and Gynecology, MCP Hahnemann University, Philadelphia, PA, USA