title: Maternal super-obesity and perinatal outcomes in Australia: a national population-based cohort study.
abstract: BACKGROUND
  Super-obesity is associated with significantly elevated rates of obstetric complications, adverse perinatal outcomes and interventions. The purpose of this study was to determine the prevalence, risk factors, management and perinatal outcomes of super-obese women giving birth in Australia.
  
  
  METHODS
  A national population-based cohort study. Super-obese pregnant women (body mass index (BMI) >50 kg/m(2) or weight >140 kg) who gave birth between January 1 and October 31, 2010 and a comparison cohort were identified using the Australasian Maternity Outcomes Surveillance System (AMOSS). Outcomes included maternal and perinatal morbidity and mortality. Prevalence estimates calculated with 95% confidence intervals (CIs). Adjusted odds ratios (ORs) were calculated using multivariable logistic regression.
  
  
  RESULTS
  370 super-obese women with a median BMI of 52.8 kg/m(2) (range 40.9-79.9 kg/m(2)) and prevalence of 2.1 per 1 000 women giving birth (95% CI: 1.96-2.40). Super-obese women were significantly more likely to be public patients (96.2%), smoke (23.8%) and be socio-economically disadvantaged (36.2%). Compared with other women, super-obese women had a significantly higher risk for obstetric (adjusted odds ratio (AOR) 2.42, 95% CI: 1.77-3.29) and medical (AOR: 2.89, 95% CI: 2.64-4.11) complications during pregnancy, birth by caesarean section (51.6%) and admission to special care (HDU/ICU) (6.2%). The 372 babies born to 365 super-obese women with outcomes known had significantly higher rates of birthweight ≥ 4500 g (AOR 19.94, 95 % CI: 6.81-58.36), hospital transfer (AOR 3.81, 95 % CI: 1.93-7.55) and admission to Neonatal Intensive Care Unit (NICU) (AOR 1.83, 95% CI: 1.27-2.65) compared to babies of the comparison group, but not prematurity (10.5% versus 9.2%) or perinatal mortality (11.0 (95% CI: 4.3-28.0) versus 6.6 (95% CI: 2.6- 16.8) per 1 000 singleton births).
  
  
  CONCLUSIONS
  Super-obesity in pregnancy in Australia is associated with increased rates of pregnancy and birth complications, and with social disadvantage. There is an urgent need to further address risk factors leading to super-obesity among pregnant women and for maternity services to better address pre-pregnancy and pregnancy care to reduce associated inequalities in perinatal outcomes.
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. elizabeth.sullivan@uts.edu.au.|School of Women's and Children's Health, The University of New South Wales, Sydney, Australia. elizabeth.sullivan@uts.edu.au.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Sullivan
authors.affiliation: School of Women's and Infants' Health, The University of Western Australia, Perth, Australia. Jan.Dickinson@uwa.edu.au.
authors.forename: Jan E
authors.initials: JE
authors.lastname: Dickinson
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Geraldine.Vaughan@uts.edu.au.
authors.forename: Geraldine A
authors.initials: GA
authors.lastname: Vaughan
authors.affiliation: Department of Obstetrics and Gynaecology Medical School College of Medicine, Biology and Environment, The Australian National University, Canberra, Australia. michael.peek@sydney.edu.au.|Obstetrics and Gynaecology, Centenary Hospital for Women and Children, Canberra, Australia. michael.peek@sydney.edu.au.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Peek
authors.affiliation: School of Medicine, Griffith University, Queensland, Australia. d.ellwood@griffith.edu.au.|Gold Coast University Hospital, Queensland, Australia. d.ellwood@griffith.edu.au.
authors.forename: David
authors.initials: D
authors.lastname: Ellwood
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Caroline.Homer@uts.edu.au.
authors.forename: Caroline S E
authors.initials: CS
authors.lastname: Homer
authors.affiliation: National Perinatal Epidemiology Unit, University of Oxford, Oxford, United Kingdom. marian.knight@npeu.ox.ac.uk.
authors.forename: Marian
authors.initials: M
authors.lastname: Knight
authors.affiliation: Obstetrics and Gynaecology, National Women's Health, Auckland City Hospital, Auckland, New Zealand. CMcLintock@adhb.govt.nz.
authors.forename: Claire
authors.initials: C
authors.lastname: McLintock
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Alex.wang@uts.edu.au.
authors.forename: Alex
authors.initials: A
authors.lastname: Wang
authors.affiliation: Judith Lumley Centre, La Trobe University, Melbourne, Australia. W.Pollock@latrobe.edu.au.|Department of Nursing, Melbourne School of Health Sciences, The University of Melbourne, Melbourne, Australia. W.Pollock@latrobe.edu.au.
authors.forename: Wendy
authors.initials: W
authors.lastname: Pollock
authors.affiliation: Muru Marri Indigenous Health Unit, School of Public Health and Community Medicine, The University of New South Wales, Sydney, Australia. lisa.jackson-pulver@unsw.edu.au.
authors.forename: Lisa
authors.initials: L
authors.lastname: Jackson Pulver
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Zhuoyang.Li@uts.edu.au.
authors.forename: Zhuoyang
authors.initials: Z
authors.lastname: Li
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Nasrin.Javid@uts.edu.au.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Javid
authors.affiliation: Faculty of Health, University of Technology Sydney, PO Box 123, Broadway NSW, 2007, Sydney, Australia. Elizabeth.Denney-Wilson@uts.edu.au.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Denney-Wilson
authors.affiliation: Royal Brisbane and Women's Hospital, Brisbane, Australia. l.callaway@uq.edu.au.|School of Medicine, The University of Queensland, Brisbane, Australia. l.callaway@uq.edu.au.
authors.forename: Leonie
authors.initials: L
authors.lastname: Callaway
mesh_terms: D000328:Adult; D001034:Apgar Score; D001315:Australia / Q000453:epidemiology; D001724:Birth Weight; D015992:Body Mass Index; D001835:Body Weight; D002585:Cesarean Section / Q000009:adverse effects; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008427:Maternal Health Services; D009767:Obesity, Morbid / Q000453:epidemiology*; D016017:Odds Ratio; D054238:Perinatal Mortality; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D055815:Young Adult