1. Key Laboratory of Diagnostic Medicine Designated by the Chinese Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing 400016, China
2. Prenatal Diagnostic Center, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510620, China
3. Department of Laboratory Medicine, Hebei General Hospital, Shijiazhuang 050051, China