Bacterial vaginosis and risk of pelvic inflammatory disease

Obstet Gynecol. 2004 Oct;104(4):761-9. doi: 10.1097/01.AOG.0000139512.37582.17.


Background: Bacterial vaginosis commonly is found in women with pelvic inflammatory disease (PID), but it is unclear whether bacterial vaginosis leads to incident PID.

Methods: Women (n = 1,179) from 5 U.S. centers were evaluated for a median of 3 years. Every 6-12 months, vaginal swabs were obtained for gram stain and culture of microflora. A vaginal microflora gram stain score of 7-10 was categorized as bacterial vaginosis. Pelvic inflammatory disease was diagnosed by presence of either histologic endometritis or pelvic pain and tenderness plus one of the following: oral temperature greater than 38.3 degrees C; sedimentation rate greater than 15 mm/hour; white blood count greater than 10,000; or lower genital tract detection of leukorrhea, mucopus, or Neisseria gonorrhoeae or Chlamydia trachomatis.

Results: After adjustment for relevant demographic and lifestyle factors, baseline bacterial vaginosis was not associated with the development of PID (adjusted hazard ratio 0.89, 95% confidence interval 0.55-1.45). Carriage of bacterial vaginosis in the previous 6 months before a diagnosis (adjusted risk ratio 1.31, 95% confidence interval 0.71-2.42) also was not significantly associated with PID. Similarly, neither absence of hydrogen peroxide-producing Lactobacillus nor high levels of Gardnerella vaginalis significantly increased the risk of PID. Dense growth of pigmented, anaerobic gram-negative rods in the 6 months before diagnosis did significantly increase a woman's risk of PID (P =.04). One subgroup of women, women with 2 or more recent sexual partners, demonstrated associations among bacterial vaginosis, Gardnerella vaginalis, anaerobic gram-negative rods, and PID.

Conclusion: In this cohort of high-risk women, after adjustment for confounding factors, we found no overall increased risk of developing incident PID among women with bacterial vaginosis.

Level of evidence: II-2

Publication types

  • Multicenter Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Cohort Studies
  • Female
  • Gardnerella vaginalis / isolation & purification*
  • Humans
  • Pelvic Inflammatory Disease / complications
  • Pelvic Inflammatory Disease / epidemiology*
  • Pelvic Inflammatory Disease / microbiology
  • Risk Factors
  • United States / epidemiology
  • Vaginosis, Bacterial / complications
  • Vaginosis, Bacterial / epidemiology*
  • Vaginosis, Bacterial / microbiology