Received: 18 April 2019
Accepted: 28 November 2019
First Online: 30 December 2019
Ethics approval and consent to participate
: The study was approved by the Second Affiliated Hospital of Army Medical University, Ethics approval number: 2016-研第024–01. Informed written and verbal consent was obtained from the infants’ parents or guardians. The trial was performed in accordance with the approved guidelines and regulations of the participating institutions.
: Not applicable.
: The authors declare that they have no competing interests.