1. Department of Obstetrics and Gynaecology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
2. Department of Paediatrics: Child and Youth Health, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
3. Discipline of Obstetrics, Gynaecology and Neonatology, University of Sydney, Sydney, Australia
4. Maternal and Fetal Health Research Centre, School of Medical Sciences, Division of Developmental Biology & Medicine, University of Manchester, Manchester, England, United Kingdom
5. Department of Nursing and Midwifery, School of Human and Health Sciences, University of Huddersfield, Huddersfield, West Yorkshire, England, United Kingdom
6. Vicki Culling Associates, Wellington, New Zealand
7. National Health and Medical Research Council Clinical Trials Centre, University of Sydney, Sydney, Australia
8. Department Obstetrics and Gynaecology, University of Auckland, Auckland, New Zealand