1. Department of Epidemiology and Biostatistics, School of Population Medicine and Public Health Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China
2. School of Public Health, LKS Faculty of Medicine the University of Hong Kong Hong Kong China
3. Department of Obstetrics Tongzhou Maternal and Child Health Hospital of Beijing Beijing China
4. Department of Pediatric Gastroenterology Dongguan Maternal and Child Health Care Hospital Dongguan China
5. Department of Obstetrics Affiliated Hospital of Jining Medical University Jining China
6. Department of Perinatal Health Jiaxian Maternal and Child Health Care Hospital Jiaxian China
7. Department of Nutrition First Affiliated Hospital of Nanchang University Nanchang China
8. Department of Obstetrics and Gynecology Peking Union Medical College Hospital Beijing China