*Nursing Care Research Center, Health Research Institute

‡Non-Communicable Pediatric Disease Research Center, Babol University of Medical Sciences, Babol

†Department of obstetrics and gynaecology, Tonekabon Branch, Islamic Azad University, Tonekabon, I.R. Iran

This study was approved by the Ethics Committee of Babol University of Medical Sciences, Babol, Iran (IR.MUBABOL.HRI.REC.1398.332).

Funded by, Health Research Institute in Babol University of Medical Sciences. The funder had only role in data collection and analysis, and had no role in decision to publish, or preparation of the manuscript.

F.G.H. and A.S.H. conceived the study and developed the study protocol. F.G.H., A.S.H., V.S.H., and M.N. revised the manuscript.

The authors declare no conflict of interest.

Correspondence to: Fatemeh Ghaffari, PhD, Nursing Care Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, I.R. Iran 46917-14141 (e-mail: [email protected]).