Nugent score related to vaginal culture in pregnant women

Objective: To relate Gram-stained smears, using the Nugent criteria, to qua ntitative and qualitative vaginal cultures in pregnant women. Methods: Two independent evaluators using the Nugent criteria, a standardiz ed method of Gram-stain interpretation designed to detect bacterial vaginos is, scored 104 vaginal smears from pregnant women. The quantitative and qua litative vaginal cultures were assessed at the same time and the results ex pressed as log(10) colony-forming units per gram of vaginal secretion. The Nugent scores were compared with the microbiologic findings. Results: The prevalence of normal, intermediate, or bacterial vaginosis vag inal nora as determined by Gram stain was 68%, 21%, and 11%, respectively. A comparison of the mean bacterial counts with the Nugent score showed a we ak negative correlation for Lactobacillus species and a positive correlatio n for gram-variable and gram-negative rods. Additional analysis revealed a strong positive correlation between the mean bacterial counts analyses of P eptostreptococcus a genus not included in the Nugent scoring system, and th e Nugent score. In addition, the Prevotella counts correlated strongly with both the Nugent score and the Peptostreptococcus counts. The quantitative counts for Lactobacillus did not vary significantly among the three defined groups of vaginal microflora; however, significant increases in the concen trations of Gardnerella vaginalis and Prevotella were found as the Nugent s core increased. Conclusion: A strong correlation was found among the gram-variable and gram -negative genera comprised by the Nugent score. Peptostreptococcus also cor related strongly with the Nugent score and with the Prevotella counts, sugg esting that this genus may play a role in determining vaginal health. (C) 2 001 by the American College of Obstetricians and Gynecologists.