1. Faculty of Forensic Medicine; Zhongshan School of Medicine, Sun Yat-sen University
2. Department of Obstetrics; The Sixth Affiliated Hospital of Sun Yat-sen University
3. Fetal Medicine Center, Department of Obstetrics and Gynecology
4. Reproductive Medicine Center; The First Affiliated Hospital of Sun Yat-sen University
5. Forensic Identification Institute of The Third Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes; Guangzhou P.R. China