title: Modified classification of Gram-stained vaginal smears to predict spontaneous preterm birth: a prospective cohort study.
abstract: OBJECTIVE
  The purpose of this study was to identify women at risk of spontaneous preterm birth through a 4-category Gram-stained vaginal smear method, not restricted to bacterial vaginosis.
  
  
  METHODS
  This was a prospective cohort study correlating Gram-stained vaginal smears in early pregnancy with spontaneous preterm birth. Smears were categorized as 'normal,' 'bacterial vaginosis-like,' 'grade I-like' (atypical gram-positive rods) or 'purulent grade I' (lactobacilli-dominated smears showing heavy leukorrhea of unknown cause).
  
  
  RESULTS
  Normal microflora were associated with a 4-fold decreased risk (95%CI 0.1-0.6, P < .001) of spontaneous preterm birth and an abnormal Gram stain with an overall adjusted odds ratio of 5.2 (95%CI 1.8-14.5, P < .001). The sensitivity of vaginal smear diagnosis for preterm birth increased from 25% with conventional scoring up to 70% with these modified criteria.
  
  
  CONCLUSIONS
  Accounting for atypical gram-positive bacteria and neutrophils on Gram-stained vaginal smears may identify a larger proportion of women at risk of preterm birth compared to diagnosis of bacterial vaginosis alone.
authors.affiliation: Department of Obstetrics and Gynaecology, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Verstraelen
authors.forename: Rita
authors.initials: R
authors.lastname: Verhelst
authors.forename: Kristien
authors.initials: K
authors.lastname: Roelens
authors.forename: Geert
authors.initials: G
authors.lastname: Claeys
authors.forename: Steven
authors.initials: S
authors.lastname: Weyers
authors.forename: Ellen
authors.initials: E
authors.lastname: De Backer
authors.forename: Mario
authors.initials: M
authors.lastname: Vaneechoutte
authors.forename: Marleen
authors.initials: M
authors.lastname: Temmerman
mesh_terms: D000328:Adult; D005260:Female; D006094:Gram-Positive Bacteria / Q000302:isolation & purification; D006801:Humans; D007778:Lactobacillus / Q000302:isolation & purification; D007964:Leukocytosis / Q000175:diagnosis; D011237:Predictive Value of Tests; D011247:Pregnancy; D011256:Pregnancy Outcome; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D047928:Premature Birth; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014621:Vagina / Q000382:microbiology*; D014626:Vaginal Smears / Q000145:classification*; D016585:Vaginosis, Bacterial / Q000175:diagnosis