Funding for this research was provided by:
the Jiangsu Commission of Health (H2019010)
the National Key R&D Program of China (2017YFC1310700 and 2017YFC1310701)
Received: 7 September 2020
Accepted: 27 January 2021
First Online: 22 February 2021
Ethics approval and consent to participate
: All participants provided written informed consent. This study was approved by the ethics committee of Soochow University and Maternal and Child Healthcare Center of Taicang.
: Not applicable.
: The authors declare that they have no competing interests.