1. Department of Midwifery, College of Medicine and Health Sciences Wollo University Dessie Ethiopia
2. Department of Reproductive and Family Health, School of Public Health, College of Medicine and Health Sciences Wollo University Dessie Ethiopia
3. Department of Epidemiology and Biostatistics, School of Public Health, College of Medicine and Health Sciences Wollo University Dessie Ethiopia
4. Department of Epidemiology University Medical Center Groningen, University of Groningen Groningen The Netherlands