1. Department of Obstetrics and Gynaecology, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
2. Department of Obstetrics and Gynaecology, Tuen Mun Hospital, Hong Kong SAR, China
3. Department of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong SAR, China
4. Department of Obstetrics and Gynaecology, Queen Elizabeth Hospital, Hong Kong SAR, China
5. Department of Obstetrics and Gynaecology, Pamela Youde Nethersole Eastern Hospital, Hong Kong SAR, China
6. Department of Obstetrics and Gynaecology, Princess Margaret Hospital, Hong Kong SAR, China
7. Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China