Wang, Xinyi
Liu, Jianghua
Lu, Weixia
Jia, Weihua
Li, Qingzhi
Traoré, Stanislav S.
Lyu, Quanjun
Article History
Received: 4 September 2022
Accepted: 13 December 2022
First Online: 20 December 2022
Declarations
:
: This is an observational study. The Medical Ethics Committee of Zhengzhou Center for Disease Control and Prevention has confirmed that no ethical approval is required.
: Written informed consent was obtained from all mothers.
: The authors declare no competing interests.