Lin, Li
Lu, Ciyong
Chen, Weiqing
Li, Chunrong
Guo, Vivian Yawei
Article History
Received: 20 December 2020
Accepted: 1 March 2021
First Online: 26 March 2021
Declarations
:
: The study has been approved by the institutional review board of Chengdu Women’s and Children’s Central Hospital and School of Public Health in Sun Yat-sen University. Since the anonymous data were respectively extracted from the electronic record without any information that could identify particular individual, a waiver of informed consent was granted by the institutional review board of Chengdu Women’s and Children’s Central Hospital and School of Public Health in Sun Yat-sen University.All methods were carried out in accordance with relevant guidelines and regulations.
: Not required.
: The authors declare that they have no competing interests.