Yang, Wan
Yang, Rui
Lin, Mingmei
Yang, Yan
Song, Xueling
Zhang, Jiajia
Yang, Shuo
Song, Ying
Li, Jia
Pang, Tianshu
Deng, Feng
Zhang, Hua
Wang, Ying
Li, Rong
Jiao, Jie
Funding for this research was provided by:
National Natural Science Foundation of China (81550022)
Article History
Received: 15 August 2018
Accepted: 13 November 2018
First Online: 19 November 2018
Ethics approval and consent to participate
: This study was approved by the Institutional Review Board of the Department of Obstetrics and Gynecology, Peking University Third Hospital. Since this is a retrospective investigation, patients were not asked to participate in this study.
: Not applicable.
: The authors declare that they have no competing interests.
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