Funding for this research was provided by:
Project of Shanghai Natural Science Foundation (20ZR1444000)
Family Planning Project of the Shanghai Health and Family Planning Commission (201640371)
Article History
Received: 17 December 2020
Accepted: 4 July 2021
First Online: 21 July 2021
Declarations
:
: Compliance with ethical standards and ethical approval is available.
: All participants signed informed consent before operation and agreed to use their biological samples for research.
: The authors declare no competing interests.