1. Unit of Population Health Information and Departments of Neonatology and Obstetrics, Huai’an Women and Children’s Hospital, Huai’an, China;
2. Departments of Pediatrics and Neonatology, Children’s Hospital of Fudan University Shanghai, Shanghai, China;
3. Departments of Pediatrics and Obstetrics, Huai’an First General Hospital, Huai’an, China;
4. Departments of Pediatrics and Obstetrics, Huai’an Second General Hospital, Huai’an, China;
5. Departments of Pediatrics and Obstetrics, Huaiyin District Hospital, Huai’an, China;
6. Departments of Pediatrics and Obstetrics, Chuzhou District Hospital, Huai’an, China;
7. Departments of Pediatrics and Obstetrics, Lianshui County Hospital, Huai’an, China;
8. Departments of Pediatrics and Obstetrics, Xuyi County Hospital, Huai’an, China;
9. Departments of Pediatrics and Obstetrics, Hongze County Hospital, Huai’an, China;
10. Departments of Pediatrics and Obstetrics, Jinhu County Hospital, Huai’an, China