CHARLESTON, S.C. — Oral and vaginal metronidazole appear to have comparable efficacy for the treatment of bacterial vaginosis in low-risk pregnant women, but neither is optimal for prevention of infectious complications at delivery, Jane Hitti, M.D., reported during the annual meeting of the Infectious Diseases Society for Obstetrics and Gynecology.
In a double-blind, placebo-controlled study of 126 women with bacterial vaginosis who were randomized at or before 20 weeks' gestation to receive either oral or vaginal metronidazole, the treatment failure rate was similar for both groups (29% for oral administration vs. 35% for vaginal administration), Dr. Hitti of the University of Washington, Seattle, reported in a poster presentation at the meeting.
The oral administration group received 250 mg of metronidazole three times daily for 1 week; the vaginal administration group was treated with 5 g of 0.75% gel twice daily for 5 days. Treatment failure was defined as persistent BV at 4 weeks after treatment, she noted.
Although treatment outcomes in regard to bacterial vaginosis persistence were statistically similar for the two groups, the rate of certain infectious complications at delivery was of concern.
For example, the cesarean wound infection rate was 33% in the oral metronidazole group, compared with 18% in the vaginal metronidazole group, 0% in a group of 47 women with intermediate Gram stain results, and 6% in a group of 190 women with normal Gram stain results.
The difference between the oral treatment group and the normal controls reached statistical significance.
Furthermore, the rate of chorioamnionitis was 20% in the vaginal treatment group, compared with 9% in the oral treatment group, 7% in the intermediate Gram stain group, and 10% in the controls. These differences did not reach statistical significance, but the findings suggest that infectious complications remain a concern in patients with bacterial vaginosis, regardless of metronidazole treatment delivery method.