[1] Univ Technol Sydney, Fac Hlth, Ctr Midwifery & Child & Family Hlth, Sydney, NSW, Australia
[2] Sydney Partnership Hlth Educ Res & Enterprise SPH, Maridulu Budyari Gumal, Sydney, NSW, Australia
[3] UNSW, UNSW Med, Sch Womens & Childrens Hlth, Sydney, NSW, Australia
[4] UNSW, Natl Perinatal Epidemiol & Stat Unit, Ctr Big Data Res Hlth, Sydney, NSW, Australia
[5] Royal Hosp Women, South Eastern Sydney Local Hlth Dist, Sydney, NSW, Australia
[6] St George Hosp, Dept Womens & Childrens Hlth, Sydney, NSW, Australia
[7] UNSW Med, George Inst Global Hlth, Sydney, NSW, Australia