Race/ethnicity, vaginal flora patterns, and pH during pregnancy

Objectives: To investigate the relationship between bacterial vaginosis dur ing pregnancy and black race/ethnicity, Study Design: Gram staining was used to evaluate vaginal flora in 842 women at 23 to 29 weeks' gestation. Results: Overall, 22.3% of blacks and 8.5% of whites had bacterial vaginosi s, Vaginal pH and flora differed significantly by race/ethnicity; blacks we re more likely to have pH greater than or equal to 4.5, no lactobacilli, sm all gram-variable and -negative rods, and Mobiluncus compared with whites ( odds ratios 1.6, 1.5, 1.4, and 10.6, respectively). Quantity of morphotypes also differed, especially for Mobiluncus. Among women with Mobiluncus pres ent (12.0% of blacks and 1.3% of whites), 73.3% of blacks compared with 40. 0% of whites had the highest level. Adjustment for sociodemographics, sexua l activity, sexually trandmitted diseases, health behavior, and sexual hygi ene did not explain these differences. Conclusion: We observed race/ethnicity differences in vaginal flora ecology . These differences may ultimately play a rule in the larger proportion of preterm deliveries among black women compared with white women.