Funding for this research was provided by:
the 2020 Innovation and Entrepreneurship Program of Jiangsu Province
Article History
Received: 28 September 2020
Accepted: 25 March 2021
First Online: 1 April 2021
Declarations
:
: Written informed consent was obtained from all participants. This study was conducted based on the Declaration of Helsinki and was approved by the Ethics Committee of Nantong Maternal and Child Healthcare Hospital (Y2018020).
: Not applicable.
: The authors declare that they have no conflict of interest.