Received: 20 May 2020
Accepted: 27 August 2020
First Online: 7 September 2020
Ethics approval and consent to participate
: An informed written consent was taken from each participant’s father or mother. This study was approved by Research Ethics Committee, Quality Assurance Unit, Faculty of Medicine, Tanta University, with the following approval code: 31542/05/17.
: The authors declare that they have no competing interests.