Article History
Received: 26 October 2020
Accepted: 13 April 2021
First Online: 29 April 2021
Declarations
:
: Our study was approved by the Ethics Review Board of Chongqing Health Center for Women and Children. The study followed the tenets of the <i>Declaration of Helsinki</i>, and the informed written consent was obtained from all patients after we explained the nature and possible consequences of the study.
: Not applicable.
: The authors declare that they have no competing interests.