1. National Research Institute for Family Planning Beijing China
2. National Human Genetic Resources Center Beijing China
3. Prenatal Diagnostic Center, Beijing Obstetrics and Gynecology Hospital Capital Medical University Beijing China
4. Gansu Province Medical Genetics Center Gansu Provincial Maternity and Child‐Care Hospital Lanzhou China
5. Department of Obstetrics and Gynecology Peking University International Hospital Beijing China
6. Department of Prenatal Diagnosis Center General Hospital of Ningxia Medical University Yinchuan China
7. Clinical Lab The Third Affiliated Hospital of Zhengzhou University Zhengzhou China