Funding for this research was provided by:
Jiangsu maternal and child health project (F201740)
Received: 20 October 2020
Accepted: 23 December 2020
First Online: 6 January 2021
Ethics approval and consent to participate
: Patients signed informed consent forms, and protocols were approved by Medical Ethical Committee at the Fourth Affiliated Hospital of Jiangsu University (Reference code: ujs5thhos20180301).
: Not applicable.
: The authors declare that they have no competing interests.