Article History
Received: 31 March 2020
Accepted: 16 October 2020
First Online: 28 October 2020
Ethics approval and consent to participate
: This article is a meta-analysis. The Women’s Hospital School of Medicine Zhejiang University Medical Ethics Committee reviewed and exempted the study. The requirement for informed consent was waived due to the nature of the study.
: Not applicable.
: The authors declare that they have no competing interest.