Li, Jiatong
Chen, Bing
Gao, Caifeng
Huang, Jing
Wang, Yongmei
Zhang, Shiyin
Xu, Ying
Guo, Wenkai
Wang, Rong
Funding for this research was provided by:
Population and Family Planning Commission of Shandong Province (2018GSF118227)
Article History
Received: 6 July 2019
Accepted: 25 November 2019
First Online: 16 December 2019
Ethics approval and consent to participate
: The data collection of related cases has been approved by the Ethics Committee of the Affiliated Provincial Hospital of Shandong University (LCYJ: No. 2019–105). Oral and written informed consent to participation is obtained from all study participants by study personnel prior to any study related procedure. All participants receive both written and oral information about the study before giving consent.
: Not applicable.
: The authors declare that they have no competing interests.