1. Tianjin Key Laboratory of Human Development and Reproductive Regulation, Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin 300100, China
2. Prenatal Diagnosis Center, Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin 300100, China
3. Radiology Department, Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin 300100, China
4. Pathology Department, Tianjin Central Hospital of Obstetrics and Gynecology/Nankai University Affiliated Maternity Hospital, Tianjin 300100, China.