Obesity as an independent risk factor for group B streptococcal colonization

J Matern Fetal Neonatal Med. 2017 Dec;30(23):2876-2879. doi: 10.1080/14767058.2016.1265937. Epub 2016 Dec 20.


Objective: Approximately 25% of women are colonized with group B streptococcus (GBS). We assessed whether body mass index (BMI) is an independent risk factor for GBS colonization.

Study design: We performed a retrospective cohort study using a previously collected database of women who delivered singleton gestations at term. Individual patient medical record review was undertaken to add GBS-related information to the database. Univariable logistic regression was used to assess the relationship between GBS colonization and BMI. Multivariable logistic regression was used to adjust for confounders.

Results: A total of 2045 patients met enrollment criteria. The prevalence of GBS colonization was 29%. In the unadjusted analysis, there was a statistically significant increase in GBS colonization per unit increase in BMI (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.04). This relationship remained significant after adjusting for confounders (race, marital status, payer, chronic hypertension, concomitant genital infections) (OR 1.01, 95% CI 1.00-1.03; p = 0.04). By BMI category, there were no differences in antibiotic susceptibilities or mode of ascertainment of GBS colonization.

Conclusion: Obesity is an independent risk factor for GBS colonization; however, this association is weak.

Keywords: Obesity; antibiotic prophylaxis; group B streptococcus; pregnancy.

MeSH terms

  • Adolescent
  • Adult
  • Body Mass Index
  • Female
  • Humans
  • Middle Aged
  • Obesity / complications
  • Obesity / epidemiology*
  • Pregnancy
  • Pregnancy Complications, Infectious / epidemiology*
  • Pregnancy Complications, Infectious / etiology
  • Prevalence
  • Retrospective Studies
  • Risk Factors
  • Streptococcal Infections / complications
  • Streptococcal Infections / epidemiology*
  • Streptococcus agalactiae / growth & development
  • Streptococcus agalactiae / isolation & purification
  • Young Adult