1. Discipline of Obstetrics, Gynaecology and Neonatology; Queen Elizabeth II Research Institute for Mothers and Infants D02; The University of Sydney; Sydney; New South Wales; Australia
2. Early Pregnancy Unit and Women's and Babies; Royal Prince Alfred Hospital; Sydney; New South Wales; Australia
3. Emergency Department; Royal Prince Alfred Hospital; Sydney; New South Wales; Australia
4. Central Clinical School; The University of Sydney; Royal Prince Alfred Hospital; Sydney; New South Wales; Australia