1. Division of Birth Cohort Study Guangzhou Women and Children’s Medical Center Guangzhou Medical University Guangzhou China
2. Nuffield Department of Women’s & Reproductive Health University of Oxford Oxford UK
3. University of New South Wales Sydney NSW Australia
4. Department of Woman and Child Health Care Guangzhou Women and Children’s Medical Center Guangzhou Medical University Guangzhou China
5. Department of Neonatal Surgery Guangzhou Women and Children’s Medical Center Guangzhou Medical University Guangzhou China
6. Department of Obstetrics and Gynecology Guangzhou Women and Children Medical Center Guangzhou Medical University Guangzhou China