1. Department of Ultrasonography, Peking University Shenzhen Hospital, Shenzhen 518036, China
2. Department of Ultrasonography, Weifang People’s Hospital, Weifang 261044, China
3. Department of Zhuhai Campus, Zunyi Medical University, Zunyi 563006, China
4. Center of Obstetrics and Gynecology, Peking University Shenzhen Hospital, Shenzhen 518036, China
5. Institute of Obstetrics and Gynecology, Shenzhen PKU-HKUST Medical Center, Shenzhen 518036, China