1. Department of Obstetrics Shenzhen People’s Hospital Shenzhen China
2. Department of Obstetrics and Gynecology The University of Hong Kong ‐ Shenzhen Hospital Shenzhen China
3. The First School of Clinical Medicine Southern Medical University Guangzhou China
4. Department of Ultrasound Shenzhen People’s Hospital Shenzhen China
5. Department of Radiology Shenzhen People’s Hospital Shenzhen China