Article History
Accepted: 12 August 2020
First Online: 26 August 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: This retrospective chart review study involving human participants was in accordance with the ethical standards of the institutional and national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The Ethics Boards of Shanghai Children’s Hospital approved this study.
Free to read: This content has been made available to all.