1. Department of Obstetrics, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China;
2. International Collaborative Joint Laboratory of Reproduction and Development of Ministry of Education of China, Chongqing Medical University, Chongqing, China;
3. State Key Laboratory of Maternal and Fetal Medicine of Chongqing Municipality, the First Affiliated Hospital of Chongqing Medical University, Chongqing, China