Department of Maternal and Child Health and MOE Key Lab of Environment and Health;
School of Public Health;
Tongji Medical College;
Huazhong University of Science and Technology;
Wuhan 430030;
China;
Maternity and Children Health Care Hospital of Luohu District;
Shenzhen 518019;
China;
Central Hospital of Longhua New District;
Shenzhen 518000;
China;