1. 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. International Collaborative Laboratory of Reproduction and Development of Chinese Ministry of Education, Chongqing Medical University, Chongqing 400016, China
4. Liggins Institute, University of Auckland, Auckland, New Zealand
5. College of Medicine, University of Leicester, Leicester LE1 7RH, UK