Definitions of the levels of evidence (I, II-1, II-2, II-3, and III) and grades of recommendations (A-E and L) are provided at the end of the "Major Recommendations" field.
There is currently no consensus as to whether to screen for or treat bacterial vaginosis in the general pregnant population in order to prevent adverse outcomes, such as preterm birth.
- In symptomatic pregnant women, testing for and treatment of bacterial vaginosis is recommended for symptom resolution. Diagnostic criteria are the same for pregnant and non-pregnant women. (I-A)
- Treatment with either oral or vaginal antibiotics is acceptable for achieving a cure in pregnant women with symptomatic bacterial vaginosis who are at low risk of adverse obstetric outcomes. (I-A)
- Asymptomatic women and women without identified risk factors for preterm birth should not undergo routine screening for or treatment of bacterial vaginosis. (I-B)
- Women at increased risk for preterm birth may benefit from routine screening for and treatment of bacterial vaginosis. (I-B)
- If treatment for the prevention of adverse pregnancy outcomes is undertaken, it should be with metronidazole 500 mg orally twice daily for seven days or clindamycin 300 mg orally twice daily for seven days. Topical (vaginal) therapy is not recommended for this indication. (I-B)
- Testing should be repeated one month after treatment to ensure that cure was achieved. (III-L)
Definitions:
Quality of Evidence Assessment*
I: Evidence obtained from at least one properly randomized controlled trial
II-1: Evidence from well-designed controlled trials without randomization
II-2: Evidence from well-designed cohort (prospective or retrospective) or case-control studies, preferably from more than one centre or research group
II-3: Evidence obtained from comparisons between times or places with or without the intervention. Dramatic results in uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category
III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees
Classification of Recommendations**
A. There is good evidence to recommend the clinical preventive action.
B. There is fair evidence to recommend the clinical preventive action.
C. The existing evidence is conflicting and does not allow to make a recommendation for or against use of the clinical preventive action; however, other factors may influence decision-making.
D. There is fair evidence to recommend against the clinical preventive action.
E. There is good evidence to recommend against the clinical preventive action.
L. There is insufficient evidence (in quantity or quality) to make a recommendation; however, other factors may influence decision-making.
*The quality of evidence reported in these guidelines has been adapted from The Evaluation of Evidence criteria described in the Canadian Task Force on Preventive Health Care.
**Recommendations included in these guidelines have been adapted from the Classification of Recommendations criteria described in the Canadian Task Force on Preventive Health Care.
