1. Department of Woman and Child Health Care Information, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
2. Department of Science Research and Education Management, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
3. Institute for Women’s Health, University College London, London, UK
4. School of Public Health, Sun Yat-sen University, Guangzhou, China