1. Department of Obstetrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
2. Women and Children’s Hospital of Chongqing Medical University, Chongqing 400014, China
3. State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China