1. Department of Obstetrics and Gynaecology, The Second Clinical College, Guizhou University of Chinese Medicine, Guiyang 550000, China
2. Reproductive Centre, Women and Children’s Hospital, Qingdao University, Qingdao 266012, China
3. Department of Obstetrics and Gynaecology, The First Clinical College, Guizhou University of Chinese Medicine, Guiyang 550000, China
4. Reproductive Centre, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
5. Department of Obstetrics, Maternal and Child Hospital of Hubei Province, Wuhan 430070, China