Vaginal hydrolytic enzymes, immunoglobulin A against Gardnerella vaginalis toxin, and risk of early preterm birth among women in preterm labor with bacterial vaginosis or intermediate flora

Objective: The purpose of this study was to determine whether the microbial hydrolytic enzymes, sialidase and prolidase, and immunoglobulin A against the Gardnerella vaginalis cytolysin (anti-Gvh IgA) increase the risk for early preterm birth (≤34 weeks of gestation) among women with bacterial vaginosis or intermediate flora. Study Design: Two hundred eighteen afebrile women in preterm labor with intact membranes had a vaginal Gram stain performed, and sialidase, prolidase, and anti-Gvh IgA concentrations were determined. Results: Women with bacterial vaginosis or intermediate flora had significantly higher sialidase and prolidase concentrations than women with normal flora. Among women with bacterial vaginosis or intermediate flora, the women with sialidase had a higher rate of early preterm birth (P =.05). Sialidase had a sensitivity of 43% and specificity of 77% for early preterm birth. Prolidase and anti-Gvh IgA did not predict early preterm birth. Conclusion: Women in preterm labor with bacterial vaginosis or intermediate flora and detectable sialidase are at increased risk of early preterm birth.