Zhang, Ying
Huang, Yijie
Ai, Tao
Luo, Jun
Liu, Hanmin
Article History
Received: 31 December 2020
Accepted: 20 April 2021
First Online: 28 April 2021
Declarations
:
: The study protocol was approved by the Chengdu Women’s and Children’s Central Hospital institutional review board (Code: NO. B2020[CitationRef removed]). The included data were retrospective data from medical records and did not include any identifying information. Consent to participate is not applicable for this study.
: No identifiable patient data or identified individual responses are used in this publication.
: All authors declare that they have no competing interests.