1. Prenatal Diagnostic Center, Beijing Obstetrics and Gynecology Hospital, Beijing Maternal and Child Health Care Hospital Capital Medical University Beijing China
2. Ultrasonic Department, Shijiazhuang Obstetrics and Gynecology Hospital Key Laboratory of Maternal and Fetal Medicine of Hebei Province Shijiazhuang China
3. Department of Stomatology Fifth Medical Center of Chinese PLA General Hospital Beijing China
4. Prenatal Diagnosis Center, Shijiazhuang Obstetrics and Gynecology Hospital Key Laboratory of Maternal and Fetal Medicine of Hebei Province Shijiazhuang China
5. Department of Orthodontics, Beijing Stomatological Hospital, Capital Medical University School of Stomatology Capital Medical University Beijing China