1. State Key Laboratory of Reproductive Medicine Nanjing Medical University Nanjing Jiangsu 211166 China
2. Key Laboratory of Pathogen Biology of Jiangsu Province Department of Microbiology Nanjing Medical University Nanjing Jiangsu 211166 China
3. Department of Obstetrics Dalian Municipal Maternal and Infant Health Care Hospital Dalian Liaoning 116000 China
4. Department of Obstetrics and Gynecology Yangzhou Maternal and Child Health Hospital Yangzhou University Yangzhou Jiangsu 225009 China
5. Department of Obstetrics and Gynecology The Second Affiliated Hospital of Nantong University Nantong Jiangsu 226001 China
6. Department of Biochemistry and Molecular Pharmacology University of Massachusetts Medical School Worcester MA 01655 USA