Received: 12 October 2019
Accepted: 11 February 2020
First Online: 9 March 2020
Ethics approval and consent to participate
: The study protocol gained approval from the Research of the Ethical Committee of the Faculty of Medicine, in Benha University (reference number is not available because this study approval had been obtained before the ethics committee started numbering). For any details, please contact Professor Dr. Nermeen Adly. Telephone: +201000071033, email: firstname.lastname@example.org. Written informed consent was obtained from the parent of the participants.
: Not applicable.
: The authors declare that they have no competing interests.