1. Department of Gynaecology, Jingzhou Central Hospital, The Second Clinical Medical College, Yangtze University, Jingzhou, Hubei 434020, P.R. China
2. Department of Anesthesiology, Jingzhou Central Hospital, The Second Clinical Medical College, Yangtze University, Jingzhou, Hubei 434020, P.R. China
3. Department of Clinical Laboratory, Center for Laboratory Medicine, Hainan Women and Children's Medical Center, Haikou, Hainan 570206, P.R. China