Liu, Xitong
Shi, Juanzi
Funding for this research was provided by:
National Natural Science Foundation of China (81771657)
Article History
Received: 24 August 2020
Accepted: 19 October 2020
First Online: 23 October 2020
Compliance with ethical standards
: This study was approved by the ethics committee of the Northwest Women’s and Children’s Hospital (number 2018002). Because of the nature of the retrospective cohort study, informed consent was therefore waived.