1. Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University , Guangzhou 510150 , China
2. Department of Obstetrics and Gynecology, Beijing Key Laboratory of Reproductive Endocrinology and Assisted Reproductive Technology and Key Laboratory of Assisted Reproduction, Ministry of Education, Center for Reproductive Medicine, Peking University Third Hospital , Beijing 100191 , China
3. National Clinical Research Center for Obstetrics and Gynecology , Beijing 100191 , China
4. Clinical Stem Cell Research Center, Peking University Third Hospital , Beijing 100191 , China