1. Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences University of Auckland Auckland New Zealand
2. Department of Women's Health Counties Manukau District Health Board Auckland New Zealand
3. Department of Pathology Counties Manukau District Health Board Auckland New Zealand
4. Department of Epidemiology and Biostatistics, Faculty of Medical and Health Sciences University of Auckland Auckland New Zealand
5. Department of Obstetrics and Gynaecology Auckland District Health Board Auckland New Zealand