1. Department of Pathology, Wuxi No2 People’s Hospital, Nanjing Medical University, Wuxi, China
2. Department of Pathology, Wuxi Maternity and Children Hospital, Nanjing Medical University, Wuxi, China
3. The Hospital of Obstetrics and Gynaecology, Fudan University, Shanghai, China
4. Centre for Reproductive Medicine, Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Shanghai, China
5. Department of Obstetrics and Gynaecology, The University of Auckland, Auckland, New Zealand