affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Sichuan University - Department of Pediatrics, affiliation not provided to SSRN and Southwest Medical University - Affiliated Hospital

Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China, Sichuan University - National Office for Maternal and Child Health Surveillance of China and Sichuan University - Department of Pediatrics

Sichuan University, Sichuan University, Sichuan University, Sichuan University, Sichuan University, Sichuan University, Sichuan University, Sichuan University - Department of Pediatrics, Sichuan University and Sichuan University - Department of Pharmacology