Zhou, Hang
Gu, Ning
Yang, Yan
Wang, Zhiqun
Hu, Yali
Dai, Yimin
Article History
Received: 24 August 2021
Accepted: 5 January 2022
First Online: 21 January 2022
Declarations
:
: All methods of the study were carried out in accordance with Declaration of Helsinki and the protocol of the retrospective study was approved by the Ethic Review Committee of Nanjing Drum Tower Hospital (reference number 2020-027-01, date of approval 2020-02-25). Written informed consent was obtained from all women enrolled in the study.
: Not applicable.
: The authors declare that they have no competing interests.