Xu, Suyan
Zhang, Hongyan
Wang, Aifeng
Ma, Yongcheng
Gan, Yuan
Li, Guofeng
Article History
Received: 21 August 2019
Accepted: 22 May 2020
First Online: 9 June 2020
Ethics approval and consent to participate
: This study was approved by the Medical Ethics Committee of the Central China Fuwai Hospital of Zhengzhou University (approval number: ZU2064–153; 2014.9.23) and was performed in accordance with the guidelines in the Declaration of Helsinki.
: Not applicable.
: The authors have no competing interests to report.