Funding for this research was provided by:
National Natural Science Foundation of China (81902131)
Shanghai Medical Academy New Star Young Medical talents training subsidy Program (Shanghai Health personnel 2020-087)
Received: 9 June 2020
Accepted: 8 October 2020
First Online: 20 October 2020
Ethics approval and consent to participate
: The present study conformed to the principles of the Declaration of Helsinki. Approval was obtained from the Research Ethics Committee of the Obstetrics and Gynecology Hospital of Fudan University (Approval Number: 2019–06), and written consent was obtained from all women in this study.
: Not applicable.
: The authors declare that they have no competing interests.