1. Nursing and Midwifery Care Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
2. Maternal-fetal Medicine Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
3. Department of Social Medicine, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
4. Department of Obstetrics and Gynecology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
5. Department of Adult Child and Midwifery, School of Health and Education, Middlesex University, London, UK.