Project Details

Associations between maternal size and health outcomes for women undergoing for caesarean section: a multicentre prospective observational study (The MUM SIZE Study)

Background: The rate of obesity in women of childbearing age is increasing in high income countries. Increased BMI is thought to be related to adverse pregnancy outcomes. During pregnancy, however, BMI may naturally increase leading to incorrect classification of women according to WHO BMI categories (underweight, normal, overweight, obese and super-obese) at term and a reluctance of clinicians and researchers to use pre-pregnancy BMI categories in term pregnant women. Furthermore, the rate of caesarean section (CS) is also increasing which, when combined with increased maternal size, may contribute to adverse maternal and neonatal outcomes, increased total theatre times and increased hospital costs. There is little research in this area. The aim of this study was to investigate associations between maternal size at term and clinical, theatre utilization and health economic outcomes for women undergoing CS.

Method: A prospective multicentre observational study was undertaken of women undergoing all categories of caesarean section. Height and weight were recorded at the initial antenatal visit and at delivery. We analysed the associations between term BMI (continuous and pregnancy specific cut-off values) and total theatre time, surgical time, anaesthesia time, maternal and neonatal adverse outcomes, total hospital admission, and theatre, costs.


A/Prof Alicia Dennis 
Dr Karen Lamb 
Ms Michelle Tew
Dr Kim Dalziel
Prof Philip Clarke 
Dr Joseph Lew
Ms Anna Parker 
Dr Elizabeth Hessian  
A/Prof Glyn Teale
Dr Scott Simmons 
Dr Dan Casalaz


Ballarat Base Hospital: Michael Shaw, Balvindar Kaur, Lucy Johnson, Gabriel Jones, Alyce Burgess

The Mercy Hospital for Women: Scott Simmons, Katrina Pirie, Anne Galati-Laguda, Leanne Pilkington

The Northern Hospital: Joseph Lew, Yasmin Lennie

Goulburn Valley Health: Arnold Beeton, Gwendolyn Liow

Sunshine Hospital: Elizabeth Hessian, Samantha Bates, Mari Kawamata, Miriam Towns, Anna Tippett, Jenny Vo

North Eastern Hospital Wangaratta: Andrew Haughton, Ben Kabbabe

The Royal Women’s Hospital: Alicia Dennis, Sarah Grant, Jacqueline de Gabriel, Ingrid Walkley, Hannah Barker.


Australian and New Zealand College of Anaesthestists Clinical Trials Network Pilot Grant, 2013.

Melbourne Medical School, The University of Melbourne, MMS Research Seed Funding Grant, 2013.

Research Publications

Dennis AT, Lamb KE, Story D on behalf of the MUM SIZE Investigators, et al. Associations between maternal size and health outcomes for women undergoing caesarean section: a multicentre prospective observational study (The MUM SIZE Study). BMJ Open 2017; 7:e015630. doi: 10.1136/bmjopen-2016-015630

Research Group

Anaesthesia, Perioperative and Pain Medicine

Faculty Research Themes

Child Health

School Research Themes

Child Health in Medicine, Critical Care, Women's Health, Infectious Diseases and Immunity

Key Contact

For further information about this research, please contact the research group leader.

Department / Centre

Critical Care

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