1 Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, and Prince of Wales Hospital, Shatin, Hong Kong SAR. Electronic address: lao-tt@cuhk.edu.hk.
2 Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, and Prince of Wales Hospital, Shatin, Hong Kong SAR. Electronic address: mankin901@gmail.com.
3 Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, and Prince of Wales Hospital, Shatin, Hong Kong SAR. Electronic address: tkwcheun88@gmail.com.
4 Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, and Prince of Wales Hospital, Shatin, Hong Kong SAR. Electronic address: lwlaw@cuhk.edu.hk.