Effect of contraceptive method on Vaginal Flora

S. L. Hillier, T. M. Hooton, Carol Winter, W. Stamm

Research output: Contribution to journalArticlepeer-review


Objective: To evaluate whether use of oral contraceptives (OC), diaphragms (DI), or cervical caps (CC) alter the vaginal microflora. In vitro data has suggested that use of the spermicide nonoxynol 9 could deplete vaginal lactobacilli. Study Design: Women attending a student health clinic who were changing methods of birth control were evaluated prior to starting the new method and for the next four consecutive weeks. Vaginal flora was assessed at each visit, and women recorded frequency of intercourse and use of the birth control method and nonoxynol 9 by diary. The group was comprised of predominantly by unmarried Caucasian women, aged 18-30, who were having vaginal intercourse 1-2 times weekly. Results: 213 women (103 OC, 75 DI, 35 CC) were recruited and followed for one month, for a total of 1065 visits Results for DI and CC use were similar, so the groups were combined. Within one week of beginning DI or CC use, vaginal colonization by E coli increased from 25% (27/111) to 49% (54/110). (P < .05, McNemar's test). The increase in E. coli colonization persisted at one month. Similarly, use of these barrier methods with nonoxynol 9 increased vaginal colonization by Enterococcus from 13% at enrollment to 35% one week after using this new method. However, use of DI and CC did not affect vaginal colonization by lactobacilli (95% vs. 93%), Q. vaginalis (36% vs. 40%), anaerobic gram negative rods (40% vs. 55%), Group B streptococci, or yeast. Vaginal colonization by coagulase negative staphylococci decreased following use of barrier methods for one month (57% vs. 37%). There was no effect on the vaginal microflora associated with OC use. Conclusions: Use of diaphragms or cervical caps with nonoxynol 9 increases vaginal colonization by E. coli and Enterococcus. but has no adverse effect on vaginal lactobacilli. Use of OC does not alter the vaginal microflora and not increase colonization by yeast.

Original languageEnglish (US)
Number of pages1
JournalInfectious Diseases in Obstetrics and Gynecology
Issue number1
StatePublished - Dec 1 1996
Externally publishedYes

ASJC Scopus subject areas

  • Dermatology
  • Obstetrics and Gynecology
  • Infectious Diseases


Dive into the research topics of 'Effect of contraceptive method on Vaginal Flora'. Together they form a unique fingerprint.

Cite this