- Correspondence to Dr Jianghong Zhao, Department of Obstetrics and Gynecology, Southern Medical University, Zhongshan, Guangdong province, China; ; Dr Yanping Yu, Department of Obstetrics and Gynecology, Xiaolan Hospital Affiliated to Southern Medical University, Zhongshan, Guangdong province, China;
- Received November 15, 2019
- Revised December 17, 2019
- Accepted December 18, 2019
- First published January 24, 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.