1. The Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
2. State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, Chongqing Medical University, Chongqing 400016, China
3. The Bishan Hospital of Chongqing, Chongqing 402760, China
4. Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangdong 510623, China