1. Department of midwifery and reproductive health, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
2. Midwifery and Reproductive Health Research Center, Shahid Beheshti University of Medical Science, Tehran, Iran
3. Department of Nursing and Midwifery, Shahrood University of Medical Science, Shahrood, Iran
4. Department of Biostatistics, School of Allied Medical science, Shahid Beheshti University of Medical Sciences, Tehran, Iran