[1] Univ Queensland, Mayne Acad Obstet & Gynecol, Fac Med, Brisbane, Qld, Australia
[2] Royal Brisbane & Womens Hosp, Dept Obstet & Gynecol, Herston, Qld, Australia
[3] Queensland Fertil Grp QFG, Brisbane, Qld, Australia
[4] John Hunter Hosp, Dept Matern & Gynecol, Newcastle, NSW, Australia
[5] Univ Newcastle, Sch Med & Publ Hlth, Newcastle, Australia
[6] Univ Queensland, Royal Brisbane & Womens Hosp, Discipline Obstet & Gynaecol, Teaching & Res, Level 6 NedHanlon Bldg,Butterfield St, Brisbane, Qld 4029, Australia