Funding for this research was provided by:
National Natural Science Foundation of China (81800448)
Guangzhou Science, Technology and Innovation Commission (201707010369)
Guangdong Medical Research Foundation (2017409)
Guangzhou Municipal Health and Family Planning Commission (20171A011258)
Text and Data Mining valid from 2019-08-13
Received: 14 April 2019
Accepted: 6 August 2019
First Online: 13 August 2019
Ethics approval and consent to participate
: This project was reviewed and approved by the institutional review board of Guangzhou Women and Children’s Medical Center. Informed consent was obtained from all individual participants or their caregivers.
: Not applicable.
: The authors declare that they have no competing interests.