1. State Key Laboratory of Reproductive Medicine, Institute of Toxicology, Nanjing Medical University, Nanjing, Jiangsu 211166, P.R. China
2. Department of Gynecology and Obstetrics, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing, Jiangsu 210004, P.R. China
3. School of Public Health, Nanjing Medical University, Nanjing, Jiangsu 211100, P.R. China