1. Department of Gynaecology, Changyi People’s Hospital, Changyi 261300, Shandong, China
2. Department of Obstetrics, Changyi People’s Hospital, Changyi 261300, Shandong, China
3. Department of Gynaecology, Zhuji Affiliated Hospital of Shaoxing University, Zhuji 311800, Zhejiang, China