1. Department of Obstetrics & Gynecology, Akbarabadi Teaching Hospital, Assistant professor of Iran University of Medical Sciences, Tehran, Iran;
2. Department of Obstetrics & Gynecology, Shariati Teaching Hospital, Professor of Tehran University of Medical Sciences, Tehran, Iran;
3. Department of Obstetrics & Gynecology, Shariati Teaching Hospital, Medical student of Tehran University of Medical Sciences, Tehran, Iran;
4. Department of Obstetrics & Gynecology, Akbarabadi Teaching Hospital, Professor of Iran University of Medical Sciences, Tehran, Iran;
5. Faculty of Medicine, University of Exeter, Exeter, UK