1. Department of Medical Anesthesiology, College of Medicine and Health Sciences, University of Gondar, Kebele 16, P.O. Box 196, Gondar, Ethiopia
2. Department of Gynecology and Obstetrics, College of Medicine and Health Sciences, University of Gondar, P.O. Box 196, Gondar, Ethiopia
3. Institute of Public Health, College of Medicine and Health Sciences, University of Gondar, P.O. Box 196, Gondar, Ethiopia