Date of Award


Degree Name

Master of Philosophy (School of Medicine)

Schools and Centres


First Supervisor

Associate Professor Shailender Mehta

Second Supervisor

Laurene Aydon


Background: Group B Streptococcus (GBS) colonization in the genital tract of pregnant women is a known contributory factor for infection in the neonate, having an impact on morbidity and mortality especially if unrecognized and untreated prior to vaginal delivery. An understanding on how certain lifestyle factors contribute to the development of GBS colonization during pregnancy will assist in aiding a modification of behavior to promote prevention and improve general health.

Aim: The aim of this study was to investigate the effect of various lifestyle factors in isolation or combination on GBS colonization during pregnancy.

Methods: A cross-sectional survey research design was conducted in a tertiary metropolitan hospital in Perth, Western Australia. Participants were a subset recruited from those enrolled in the Probiotics in Pregnancy (PIP) trial. Recruitment occurred between 16-25 weeksgestation and prior to interventions taking place for the PIP trial. Lifestyle questionnaires and medical data were collected to investigate an association of lifestyle factors for GBS colonization. Univariate and multivariate analyses were performed to identify risk factors amongst the variables explored.

Results: A total of 199 multiethnic pregnant women between 16-25 weeks gestation were enrolled with an overall GBS colonization rate of 20% in this cohort. Using univariate analysis, significant association with increased GBS colonization was noted with obesity (p=0.026) and lack of exercise (p.=0.027). Intake of yoghurt during pregnancy was inversely related to GBS colonization (p=0.051). On multivariate analysis, moderate to high sugary drink intake(p.=0.029, OR 6.25, CI 0.03-0.91), and the presence of vaginal discharge (p.=0.01,OR 5.12, CI 1.36-19.24) continued to be significant.

Conclusion: Our study found significant association between certain lifestyle factors and GBS colonization in pregnancy. Further studies with larger sample size and interventional designs are warranted to explore further links and mechanisms behind identified lifestyle risk factors and GBS colonization.

Keywords: Lifestyle, Group B Streptococcus (GBS), pregnancy, neonatal