1. Clinical Research Center For Placental Medicine In Hunan Province Changsha City China
2. Department of Obstetrics Hunan Provincial Maternal and Child Health Care Hospital Changsha City China
3. NHC key labratory of birth defects for research and prevention, Hunan Provincial Maternal and Child Health Care Hospital Changsha City China
4. Department of Pediatrics Hunan Provincial Maternal and Child Health Care Hospital Changsha City China
5. Department of Reproductive Medicine Affiliated Hospital of Weifang Medical University Weifang China