Document is current

Article History

Received: 3 September 2020

Accepted: 10 May 2022

First Online: 8 June 2022

Declarations

:

: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

: All procedures performed in studies were in accordance with the ethical standards of the institutional and/or national research committee (the Dalian Municipal Maternal and Child Health Care Hospital) and with the 1964 Declaration of Helsinki and its later amendments.

: Informed consent was obtained from all individual participants included in the study.

: Not applicable.