Race/ethnicity, Vaginal Flora Patterns, and pH During Pregnancy

Sex Transm Dis. 1999 Feb;26(2):96-102. doi: 10.1097/00007435-199902000-00007.


Objectives: To investigate the relationship between bacterial vaginosis during pregnancy and black race/ethnicity.

Study design: Gram staining was used to evaluate vaginal flora in 842 women at 24 to 29 weeks' gestation.

Results: Overall, 22.3% of blacks and 8.5% of whites had bacterial vaginosis. Vaginal pH and flora differed significantly by race/ethnicity; blacks were more likely to have pH > or = 4.5, no lactobacilli, small 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 present (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, sexual activity, sexually transmitted diseases, health behavior, and sexual hygiene did not explain these differences.

Conclusion: We observed race/ethnicity differences in vaginal flora ecology. These differences may ultimately play a role in the larger proportion of preterm deliveries among black women compared with white women.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • African Continental Ancestry Group*
  • Bacteria / isolation & purification
  • Cohort Studies
  • European Continental Ancestry Group*
  • Female
  • Humans
  • Hydrogen-Ion Concentration
  • Obstetric Labor, Premature / ethnology
  • Pregnancy
  • Pregnancy Complications, Infectious / diagnosis
  • Pregnancy Complications, Infectious / ethnology*
  • Pregnancy Complications, Infectious / microbiology
  • Vagina / microbiology*
  • Vaginosis, Bacterial / diagnosis
  • Vaginosis, Bacterial / ethnology*
  • Vaginosis, Bacterial / microbiology