He, Wanhong
Sun, Υuhua
Zhang, Sufen
Feng, Xing
Xu, Minjie
Dai, Jianfeng
Ni, Xiaohua
Wang, Xin
Wu, Qihan http://orcid.org/0000-0002-6529-4877
Funding for this research was provided by:
Major Research Plan (81872103, 81971917)
Science and Technology Climbing Fund of SIPPR (PD2017-2, PD2017-4)
Article History
Received: 19 December 2019
Accepted: 19 May 2020
First Online: 23 June 2020
Compliance with ethical standards
:
: The authors declare that they have no conflict of interest.
: This study was approved by the Medical Ethics Committee of Shanghai Institute of Planned Parenthood Research. All procedures performed in studies involving human participants were in accordance with the ethical standards of NHFPC Ethical Review of Human Biomedical Research (2010) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.