1. Department of Obstetrics and Gynecology Assisted Reproductive Technology Unit Prince of Wales Hospital The Chinese University of Hong Kong Shatin, Hong Kong SAR China
2. Department of Obstetrics and Gynecology Maternal Fetal Medicine UnitPrince of Wales HospitalThe Chinese University of Hong Kong Shatin, Hong Kong SAR China
3. Department of Gynecology The First Affiliated Hospital of Chongqing Chongqing China
4. Department of Ultrasound Hubei Women and Children’s Hospital Wuhan China