Liu, Xitong
Article History
Received: 12 January 2022
Accepted: 10 March 2022
First Online: 17 March 2022
Declarations
:
: The study was granted ethical approval by the Ethics Committee of Northwest Women’s and Children’s Hospital (number 2021002). Because of the retrospective character of the study, informed consent was waived. Administrative permissions were required to access and use medical records from the corresponding author and were granted by the data protection officers of the hospital. All methods were performed in accordance with the relevant guidelines and regulations.
: Not applicable.
: None.