Article History
Received: 26 June 2021
Accepted: 1 November 2021
First Online: 7 November 2021
Declarations
:
: The authors declare that they have no conflict of interest.
: Approved by the ethics committee of West china hospital of Sichuan university (2013(201)).
: Written informed consent was obtained from all parturients before enrollment.
: Patients signed informed consent regarding publishing their data.