1. Department of Maternal and Child Health, School of Public Health, Peking University, Beijing, China
2. Environmental and Spatial Epidemiology Research Center, National Human Genetic Resources Center, Beijing, China
3. Reproductive Medical Centre, Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, China
4. National Research Institute for Family Planning, Beijing, China
5. Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
6. Center on the Early Life Origins of Disease, Department of Population, Family and Reproductive Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
7. Department of Pediatrics, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
8. Department of Maternal and Child Health, National Health Commission of the People’s Republic of China, Beijing, China