Usefulness of the preservation in Stuart medium in the determination of the balance of vaginal content

The aim of this study was to compare the use of Stuart transport medium and the conventional procedure in the determination of the Nugent score and the vaginal inflammatory response (VIR) in vaginal swabs obtained following the guidelines regarding balance of vaginal content (BAVACO). Fifty-eight symptomatic and asymptomatic pregnant women were included in this study. Two samples of vaginal content were obtained from each patient. One sample was processed as indicated in the BAVACO guide and the second one was transported and kept in Stuart medium for four hours before processing the smears. Nugent score and leucocyte count were performed on Gram stained smears (1.000X). The leucocyte count was also performed on the Giemsa stained smears (400X). The Nugent score was statistically similar for each of the numeric values between the samples using the regular procedure and the ones using Stuart medium. Kappa coefficient was 1.00. The leucocyte count was sensitively lower in all 58 cases, when Stuart medium was used. When Gram stain was performed, the correlation coefficient was 0.612. Samples of vaginal content transported with Stuart medium resulted adequate for the determination of the Nugent score. However, the VIR in samples transported in Stuart medium need to be determined by means of the leucocyte count per epithelial cell per microscopic field.