FEW MICROORGANISMS ASSOCIATED WITH BACTERIAL VAGINOSIS MAY CONSTITUTETHE PATHOLOGICAL CORE - A POPULATION-BASED MICROBIOLOGIC STUDY AMONG 3596 PREGNANT-WOMEN

OBJECTIVE: To evaluate the association between various microorganisms isolated from the genital tract in pregnant women with bacterial vagin osis. STUDY DESIGN: A cross-sectional population-based study among pre gnant women addressed at their first antenatal visit before 24 full ge stational weeks from the referring area of the Department of Obstetric s and Gynecology at Odense University Hospital, Denmark, from November 1992 to February 1994. The main outcome measures were prevalence of v arious microorganisms and statistical estimates of interactions (crude , adjusted, and relative odds ratios) between the microorganisms isola ted from the lower genital tract in pregnant women with and without cl inical diagnosis of bacterial vaginosis. RESULTS: Three thousand five hundred ninety-six (3596) pregnant women were asked to participate. Of the 3596 pregnant women 3174 (88.4%) agreed to participate before 24 full gestational weeks. After controlling for the presence of other mi croorganisms, strong associations between Gardnerella vaginalis, anaer obic bacteria, Mycoplasma hominis, and present bacterial vaginosis wer e found. Similarly Lactobacillus spp. were found to be associated with the absence of bacterial vaginosis. The combination of G. vaginalis a nd anaerobic bacteria and/or M. hominis was found in 59.6% of the case s with bacterial vaginosis and in 3.9% of the cases without bacterial vaginosis (odds ratio 36.4, 95% confidence interval 27.8 to 47.8). The crude odds ratio was found to be as high as 74.8 (95% confidence inte rval 32.3 to 174.1) when the combination of G. vaginalis, M. hominis, anaerobic bacteria, and no Lactobacillus spp. was associated with bact erial vaginosis, CONCLUSION: There is a microbial foundation for bacte rial vaginosis, and it is possibly due to an intermicrobial interactio n in which the microorganisms G. vaginalis, anaerobic bacteria, and M. hominis are dominating, indicating that these constitute the patholog ic core of bacterial vaginosis.