1. Center for Reproductive Medicine, Key Laboratory for Major Obstetric Diseases of Guangdong Province, Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, PR China
2. National Engineering Research Center for Tissue Restoration and Reconstruction, South China University of Technology, Guangzhou, Guangdong, PR China
3. Beijing Chao-Yang Hospital, Capital Medical University, Beijing, PR China