Yang, Yingzi
Li, Weiqin
Yang, Wen
Wang, Leishen
Liu, Jinnan
Leng, Junhong
Li, Wei
Wang, Shuo
Li, Jing
Hu, Gang
Yu, Zhijie
Yang, Xilin
Article History
Received: 2 December 2020
Accepted: 8 April 2021
First Online: 28 May 2021
Declarations
:
: This study was approved by the Ethics Committee for Clinical Research of Tianjin Women and Children’s Health Centre (TWCHC) on 1 December 2009 (Approval number: 2009–02) and conducted in accordance with Helsiki Declaration. Written informed consent was obtained from all the subjects before data collection and the private information in the study was well protected.
: All the authors agreed to publish the current article.
: All the authors did not have conflict of interest.