Yan, Qin
Li, Dandan
Yin, Xiaoxv
Jiang, Nan
Sun, Na
Luo, Qing
Pang, Xin
Fan, Lichun
Gong, Yanhong
Funding for this research was provided by:
National Natural Science Foundation of China (71663016)
Article History
Received: 8 November 2021
Accepted: 19 July 2022
First Online: 4 August 2022
Declarations
:
: All procedures were performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. The study was approved by the Ethics Committee of Maternal and Child Health Hospital of Hainan Province (reference number: HNWCMC201605). All the respondents participated voluntarily and informed consent was obtained before the investigation.
: Not applicable.
: The authors declare that they have no competing interests.