1. Department of Gynaecology and Obstetrics, Hainan Hospital Affiliated to University of South China, Haikou, Hainan 570311, P.R. China
2. Key Laboratory of Cell and Molecular Genetic Translational Medicine in Hainan Province, Hainan General Hospital, Haikou, Hainan 570311, P.R. China
3. Department of Gynaecology and Obstetrics, Hainan General Hospital/Hainan Affiliated Hospital of Hainan Medical University, Haikou, Hainan 570311, P.R. China