Acknowledgements
The present article is the result of a master's thesis, approved by the Ethics Committee of Mashhad University of Medical Sciences (IR.MUMS.NURSE.REC.1398.029), Mashhad, Iran. The authors' gratitude the support of the Research Vice Chancellor of Mashhad University of Medical Sciences and also the head, midwives and physicians of Umm Al-banin Hospital. Also, we appreciate all pregnant women` participation, support and cooperation. The cooperation of Umm Al-banin Hospital staff is appreciated as well. This study was registered in the Iran Clinical Trial Center with the code of IRCT20190805044446N1.