1. Department of Laboratory Medicine, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
2. Beijing Maternal and Child Health Care Hospital, Beijing, China
3. Department of Information and Statistics, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
4. Central Laboratory, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China
5. Information Center, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China