Funding for this research was provided by:
the Health commission of Zhejiang Province (2018KY440)
Received: 18 September 2018
Accepted: 25 February 2021
First Online: 5 March 2021
Ethics approval and consent to participate
: This project was approved by the Ethics Committee of Women’s Hospital, Zhejiang University School of Medicine (project 20170186), and written informed consent was obtained from the patients enrolled in this study.
: Not applicable.
: The authors declare that they have no competing interests.