1. Center for Reproduction and Genetics, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
2. Center for Reproduction and Genetics, Suzhou Municipal Hospital, Suzhou, Jiangsu, China
3. Center for Medical Ultrasound, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, Jiangsu, China
4. Center for Medical Ultrasound, Suzhou Municipal Hospital, Suzhou, Jiangsu, China