Wu, Jiang-Nan
Li, Ming-Qing
Xie, Feng
Zhang, Bin
Article History
Received: 10 June 2021
Accepted: 23 November 2021
First Online: 24 December 2021
Declarations
:
: The study was approved by the Ethics Committee of the Obstetrics and Gynecology Hospital of Fudan University (No. 2017–35, 2017–35-C1) and was conducted following Chinese law and the Guidelines of the National Human Biomedical Research Policies. No informed consent was obtained from the patients because the study was retrospective. The informed consent was waived by the Ethics Committee of the Obstetrics and Gynecology Hospital of Fudan University. Administrative permissions for the data were acquired by the authors for research purposes.
: Not applicable
: The authors declare that they have no competing interests.