Yin, Chan
Tong, Lili
Nie, Dan
Fei, Zhihui
Tan, Xiaoqun
Ma, Mingxiang
Article History
Received: 27 April 2021
Accepted: 16 December 2021
First Online: 3 January 2022
Declarations
:
: This study was approved by the Ethics Committee of the Maternal and Child Health Hospital of Changde city. Written informed consent was obtained prior to examination from all participants. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Written informed consent was obtained from the pregnant woman or patient’s parent for their personal or clinical details along with identifying images to be published in this study.
: The authors declare that they have no competing interests.