1. Division of Birth Cohort Study, Guangzhou Women and Children's Medical Center Guangzhou Medical University Guangzhou China
2. The First Affiliated Hospital of Sun Yat‐Sen University, Sun Yat‐Sen University Guangzhou China
3. Paediatrics School Guangzhou Medical University Guangzhou China
4. National Perinatal Epidemiology Unit, Nuffield Department of Population Health University of Oxford Oxford UK
5. Sun Yat‐Sen Memorial Hospital, Sun Yat‐Sen University Guangzhou China