[1] Maternal Crit Care, Melbourne, Vic, Australia
[2] Univ Melbourne, Dept Nursing, Melbourne, Vic, Australia
[3] La Trobe Univ, Sch Nursing & Midwifery, Melbourne, Vic, Australia
[4] Australian Natl Univ, Coll Hlth & Med, ANU Med Sch, Obstet & Gynaecol, Canberra, ACT, Australia
[5] Univ Technol Sydney, Fac Hlth, Australian Ctr Publ & Populat Hlth Res, Sydney, NSW, Australia
[6] Griffiths Univ, Dept Obstet & Gynaecol, Southport, Qld, Australia
[7] Burnet Inst, Maternal & Child Hlth, Melbourne, Vic, Australia
[8] Univ Sydney, Indigenous Strategy & Serv, Sydney, NSW, Australia
[9] Univ Auckland, Auckland City Hosp, Natl Womens Hlth, Auckland, New Zealand
[10] Univ Oxford, Nuffield Dept Populat Hlth, Natl Perinatal Epidemiol Unit, Maternal & Child Populat Hlth, Oxford, England
[11] Univ Newcastle, Fac Hlth & Med, Newcastle, NSW, Australia