- Correspondence to Dr Chunlin Chen, Department of Obstetrics and Gynecology, Southern Medical University Nanfang Hospital, Guangzhou 510515, China;
- Received April 24, 2020
- Revision received June 27, 2020
- Accepted June 30, 2020
- First published July 22, 2020.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.