1. Information Management Division, Hunan Provincial Maternal and Child Health Hospital, Changsha, Hunan, China
2. Division of Medical Genetics, Hunan Provincial Maternal and Child Health Hospital, Changsha, Hunan, China
3. Enrollment and Employment Office, Hunan University of Traditional Chinese Medicine, Changsha, Hunan, China
4. Reproductive Medicine Center, Hunan Provincial Maternal and Child Health Hospital, Changsha, Hunan, China
5. Maternity Department, Hunan Provincial Maternal and Child Health Hospital, Changsha, Hunan, China
6. Department of Epidemiology and Health Statistics, School of Public Health, Central South University, Hunan, China