Funding for this research was provided by:
National Basic Research Program of China (973 Program) (2016YFC1000703, 2016YFC1000700)
Medical Scientific Research Foundation of Guangdong Province, China (B2017057)
Text and Data Mining valid from 2019-04-11
Received: 21 November 2018
Accepted: 18 March 2019
First Online: 11 April 2019
Ethics approval and consent to participate
: This study was performed with the approval of the Medical Ethics Committee of Guangdong Women and Children Hospital, and written informed consent was obtained from the patients.
: The patients in this study provided their consent for its publication.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.