Article History
Received: 9 October 2021
Accepted: 12 September 2022
First Online: 29 September 2022
Declarations
:
: The authors declare that they have no conflict of interest.
: All of the subjects had agreed with the informed consents and the procedures in this study were supervised by Liaocheng Dongchangfu District Maternal and Child Health Hospital’ ethics committee. The procedures used in this study adhere to the tenets of the Declaration of Helsinki.
: Written informed consent was obtained from the parents.
: Not applicable.