Associations between vaginal bacteria and levels of vaginal defensins in pregnant women

OBJECTIVE: We evaluated vaginal defensin concentrations and levels of bacterial vaginosis-associated bacterial species in pregnant women. STUDY DESIGN: Self-collected vaginal swabs from 2 visits during pregnancy were tested with quantitative polymerase chain reaction for 9 bacterial species. Beta defensins 2-3 and alpha defensins 1-3 were measured by enzyme-linked immunosorbent assay. RESULTS: Our 126 participants were primarily African American (60%), had a mean gestational age at enrollment of 10 +/- 3 weeks and at follow-up visit of 25 +/- 6 weeks. At enrollment, the prevalence of bacterial vaginosis was 74% (94/126 women), which decreased to 60% (75/126 specimens) at follow-up visit. At enrollment, beta defensin 3 concentrations were significantly lower in women with bacterial vaginosis (2.64 +/- 0.91 vs 3.25 +/- 0.99 log(10) pg/mL; P = .003). Higher concentrations of Atopobium vaginae, bacterial vaginosis-associated bacteria1 and 2 were associated with significantly lower concentrations of beta defensin 3 (P < .01). CONCLUSION: Bacterial vaginosis was associated with lower vaginal concentrations of beta defensin 3, but not beta defensin 2 or alpha defensins 1-3, in pregnant women.