1 Department of Obstetrics and Gynaecology, National University Hospital, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore. Electronic address: pradip_dashraath@nuhs.edu.sg.
2 Department of Obstetrics and Gynaecology, National University Hospital, Singapore.
3 Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore.
4 Department of Pathology, National University Hospital, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
5 Department of Obstetrics and Gynaecology, National University Hospital, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
6 Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore; Yong Loo Lin School of Medicine, National University of Singapore, Singapore.