1. Department of Obstetrics, Obstetrics and Gynecology Hospital Fudan University Shanghai China
2. Shanghai Key Laboratory of Female Reproductive Endocrine‐Related Diseases Shanghai China
3. Center for Medical Ultrasound The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital Suzhou China
4. Medical Center of Diagnosis and Treatment for Cervical Disease Obstetrics and Gynecology Hospital of Fudan University Shanghai China
5. Department of Clinical Epidemiology, Obstetrics and Gynecology Hospital Fudan University Shanghai China