Tang, Yunhui
Chen, Yan
Feng, Hua
Zhu, Chen
Tong, Mancy
Chen, Qi
Article History
Received: 31 March 2020
Accepted: 24 September 2020
First Online: 8 October 2020
Ethics approval and consent to participate
: This study was approved by the ethics board of The Hospital of Obstetrics & Gynaecology of Fudan University and Tengzhou Central People’s Hospital. Patient consent was waived by the ethics committee of The Hospital of Obstetrics & Gynaecology of Fudan University and Tengzhou Central People’s Hospital.
: Not applicable.
: None of the authors have a conflict of interest.