Sun, Xue-Cheng
Wang, Hu
Li, Jian-hui
Zhang, Dan
Yin, Li-Qiang
Yan, Yu-Fang
Ma, Xu
Xia, Hong-Fei
Funding for this research was provided by:
National Key Research and Development Program of China (2016YFC1000803)
Article History
Received: 3 February 2020
Accepted: 4 July 2020
First Online: 3 August 2020
Ethics approval and consent to participate
: The study was approved by the ethics committee of the National Research Institute for Family Planning.
: Not applicable.
: The authors declare that they have no competing interests.