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Clinical and Cervical Cytokine Response to Treatment With Oral or Vaginal Metronidazole for Bacterial Vaginosis During Pregnancy: A Randomized Trial

From St. Michael’s Hospital, Toronto, Ontario, Canada; University of Minnesota, Minneapolis, Minnesota; Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine; and Magee-Womens Research Institute, Pittsburgh, Pennsylvania.

Address reprint requests to: Sharon L. Hillier, PhD, Magee-Womens Hospital, Department of Obstetrics, Gynecology, and Reproductive Sciences, 300 Halket Street, Pittsburgh, PA 15213; E-mail: shillier{at}mail.magee.edu.

	ABSTRACT

TOP ABSTRACT MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
OBJECTIVE: To compare the efficacy of oral versus vaginal metronidazole treatment in pregnant women with bacterial vaginosis, and to compare cytokine profiles (interleukin-1ß, -6, and -8) in the cervical secretions of these women before and after treatment.

METHODS: Pregnant women with bacterial vaginosis diagnosed both by Gram stain and clinical criteria were randomized to receive oral (n = 52) or vaginal (n = 50) metronidazole therapy. Cervical specimens for cytokine analysis and vaginal fluid for evaluation of bacterial vaginosis were obtained at baseline and 4 weeks after treatment.

RESULTS: There was no significant difference in therapeutic cure rates (defined as a Gram stain score of 0–3 and the absence of all four clinical signs of bacterial vaginosis) between the two groups (71% and 70% for the oral and vaginal groups, respectively, P = 1.0). Cervical levels of interleukin-1ß, -6, and -8 were significantly lower after treatment among the 72 women cured of bacterial vaginosis (P < .001, P = .001, and P = .02, respectively) but not among women who failed to respond to therapy. For interleukin-1ß and -6, a significant decrease in cytokine level was observed in both the oral and vaginal treatment groups.

CONCLUSION: One week of oral metronidazole and 5 days of intravaginal metronidazole are equally efficacious for treatment of bacterial vaginosis during pregnancy. The decrease in cervical interleukin-1ß, -6, and -8 levels among women who established a normal flora after treatment but not among those with persistent bacterial vaginosis suggests a direct linkage between vaginal flora abnormalities and elevated cervical levels of interleukin-1ß, -6, and -8.

Bacterial vaginosis has been linked with preterm labor and delivery, chorioamnionitis, postpartum endometritis, postcesarean delivery wound infections, postsurgical infections, and subclinical pelvic inflammatory disease.^1–8 Treatment trials in pregnancy have evaluated the use of oral metronidazole and topical clindamycin for prevention of preterm birth. The rate of preterm birth was reduced among high-risk women with the administration of systemic (oral) therapy in three randomized, placebo-controlled trials,^9–11 but no reduction in pre-term birth was observed when women were treated with two 2-g doses of oral metronidazole.¹² The 2002 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines advise against the use of topical clindamycin cream for bacterial vaginosis during pregnancy.¹³ This recommendation is based on studies that either failed to demonstrate a decrease in preterm delivery despite adequate treatment or showed trends toward an increased incidence of low birth weight, pre-term birth, or perinatal infections.^14–17 It is unclear why topical therapy might not be as effective as systemic treatment for the prevention of preterm birth, although some authors have hypothesized that systemic therapy might be required to fully eradicate bacterial vaginosis–associated organisms from both the lower and the upper genital tract, thereby preventing preterm labor and delivery.^14,15

The mechanisms linking bacterial vaginosis and adverse obstetric and gynecologic sequelae are unclear. It was once believed that pathogenic microorganisms alone were responsible for these poor outcomes. It has recently been established, however, that many of these sequelae are mediated by endogenous host products,¹⁸ and it has been hypothesized that this association might be explained by the spread of bacteria and inflammation from the lower to the upper genital tract. Alternatively, colonization of the cervix or upper genital tract by certain cervicovaginal microorganisms might be accompanied by local biochemical changes, including alterations in cytokines at the cervical level. For example, the increased concentration of bacterial endotoxin found in the vaginal fluid of women with bacterial vaginosis has been associated with an increase in proinflammatory cytokines, such as interleukin-1 in the cervical mucus.¹⁹

It has been demonstrated that the levels of certain cytokines in the lower genital tract are altered in the presence of bacterial vaginosis. Interleukin-1, -1ß, and -8 are proinflammatory cytokines that have been found to be elevated in the cervical secretions of both pregnant and nonpregnant women with bacterial vaginosis.^19–22 Studies assessing levels of interleukin-6, a cytokine with both pro- and anti-inflammatory properties, have not demonstrated a correlation with bacterial vaginosis, and it has not been consistently elevated or decreased in women with this syndrome.^20,21

The purpose of the current study was two-fold. The first objective was to compare the efficacy of oral and vaginal metronidazole treatment in pregnant women with bacterial vaginosis. The second aim was to evaluate how cytokine levels (interleukin-1ß, -6, and -8) in the cervical secretions of women are altered before and after treatment, comparing systemic and topical therapy. Comparing the response of cervical cytokines with the two routes of metronidazole therapy afforded the opportunity to evaluate whether topically applied metronidazole, which would be expected to act primarily in the lower genital tract, would yield an effect similar to that seen with oral metronidazole, which should act systemically to clear both lower and upper genital tract infection. If abnormalities in cervical cytokines were due primarily to upper tract infection, then one would expect to observe changes in cervical cytokine profiles only among women treated with oral metronidazole, and decreases in interleukin-1ß would not necessarily be linked with normalization of the vaginal flora. Our hypothesis was that cervical cytokine abnormalities among women with bacterial vaginosis are attributable to alterations in vaginal flora and the resulting increase in endotoxin levels.

	MATERIALS AND METHODS

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This study was approved by the Magee-Womens Hospital institutional review board. Pregnant women of no more than 24 weeks’ gestation with bacterial vaginosis were recruited from the Magee-Womens Hospital out-patient clinics in Pittsburgh, Pennsylvania, from December 2000 to July 2002. Bacterial vaginosis was defined as a Gram stain score of 7–10 (based on the criteria described by Nugent et al²³) plus three or more clinical signs (homogeneous vaginal discharge, amine odor with the addition of potassium hydroxide, 20% or more clue cells on saline microscopy, and pH of at least 4.7).²⁴ Women were excluded from participation if they were more than 24 weeks’ gestation, had other vaginal or cervical infections or current vaginal bleeding, or had used intravaginal products (douches, spermicides, or antifungal medications) in the preceding 24 hours.

After obtaining written, informed consent, a standardized history was obtained, and a physical examination was performed. All subjects were interviewed and examined by the same investigator (MHY). Baseline data collection included demographic characteristics; medical history, including recent antibiotic, tobacco, and drug use; and current practices, including use of douches and number of recent sexual partners. Symptoms were reported by 72 (71%) of the women at the time of enrollment. A nonlubricated speculum was used to collect vaginal fluid from the lateral vaginal walls with Dacron (Fisherbrand, Fisher Scientific, Pittsburgh, PA) swabs, and a vaginal smear for Gram stain was prepared. Vaginal fluid was evaluated for clue cells, white blood cells, motile trichomonads, and yeast with normal saline and potassium hydroxide microscopy at 100x and 400x magnification. Clue cells were identified as vaginal epithelial cells with such a heavy coating of bacteria that the peripheral borders were obscured.²⁵ Yeast was identified by the presence of pseudohyphae and spores. Vaginal fluid was also tested for pH and for the liberalization of amine odor with the addition of potassium hydroxide. Vaginal discharge was defined as homogeneous if it was nonviscous and adherent.²⁶

Specimens for cytokine collection were obtained from the endocervical canal with two Dacron swabs. Each swab was placed in the canal for 10 seconds to achieve saturation and was then placed in a plastic tube containing 0.4 mL of phosphate-buffered solution (final dilution of 1:5). Specimens were stored at -20C until the time of cytokine assay analysis.

After the history and physical examination were completed, subjects were randomized with equal frequency to one of two treatment arms with a permuted block randomization schedule, with a block size of 16. Group allocation occurred by the opening of sequentially numbered, sealed, opaque envelopes. The two treatment arms were systemic (oral) and topical (vaginal) metronidazole therapy. Subjects randomized to the systemic treatment arm received oral generic metronidazole 500 mg twice daily for 7 days. Subjects randomized to the topical treatment arm received intravaginal metronidazole gel 0.75% (Metrogel Vaginal, 3M Pharmaceuticals, St. Paul, MN), 5 g daily for 5 days. Subjects were instructed to avoid douching and intercourse during the period of treatment. No placebo controls were used in an effort to double-blind the study because of possible effects of a vaginally applied placebo gel on the vaginal microflora. Blinding of personnel evaluating microbiologic cure was maintained by withholding treatment group assignment information from laboratory investigators.

Patients were seen in follow-up 4 weeks later (median 28 days, range 14–58). At this time, a standardized history was performed that assessed compliance with therapy (by patient report) and the presence of any symptoms of infection. Perfect compliance was defined as taking all medications as prescribed, with no missed doses. The same standardized physical examination that was performed at the first visit was repeated, and subjects were evaluated for cure of bacterial vaginosis after treatment. Microbiologic cure was defined as a Gram stain score of 0–3. Clinical cure was defined as the absence of all four clinical signs (no homogeneous discharge, no amine odor after the addition of potassium hydroxide, no clue cells on saline microscopy, and pH less than 4.7). A therapeutic cure was met when both clinical and microbiologic cure was detected. These are the criteria for evaluation of cure recommended by the US Department of Health and Human Services, Food and Drug Administration in their guidance document.²⁷

Vaginal smears were Gram stained and evaluated for bacterial vaginosis according to a standardized scoring system, with a score of 0–3 indicating normal (Lactobacillus-predominant) flora, 4–6 corresponding to flora with reduced numbers of Lactobacilli relative to other bacterial morphotypes, and 7–10 consistent with bacterial vaginosis.²³ Gram stains were evaluated by laboratory technologists who were masked to treatment group and clinical signs.

Specimens for cytokine identification were stored at -20C and thawed at room temperature just before the assays were performed. For each study subject, cytokine immunoassays were performed to quantify the levels of interleukin-1ß, -6, and -8 from the enrollment and follow-up visits. Samples were coded and assayed, masked to clinical or microbiologic cure status. Commercially available cytokine kits (Quantikine, R&D Systems, Minneapolis, MN) were used. Standards and samples were added to a 96-well, precoated plate and allowed to incubate. After incubation, the plate was washed with buffer, and cytokine conjugate was added to each well. After another incubation period and buffer wash, substrate solution was added to each well. A short final incubation period then occurred and was followed by the addition of stop solution to stop all reactions. Within 30 minutes of assay completion, the optical density of each well was determined by reading the plate at a microplate reader at 450 nm. The minimum detectable levels of interleukin-1ß, -6, and -8 are less than 1 pg/mL, less than 0.7 pg/mL, and 3.0 pg/mL, respectively. Cytokine dilutions were 1:10, 1:4, and 1:20 for interleukin-1ß, -6, and -8, respectively. Each assay has an intra- and interassay variation of less than 10%. Assay results that fell outside the linear portion of the standard curve were repeated.

All statistical analyses were performed with SPSS 10.1.4 statistical software (SPSS Inc., Chicago, IL). Fisher exact test (two-tailed) was used to compare categoric variables and cure rates between the two treatment groups. The cytokine levels at enrollment and follow-up did not appear to be normally distributed when graphically displayed. In addition, the values of the skewness and kurtosis statistics indicated a significant departure from symmetry. Therefore, Wilcoxon signed rank tests were used to compare cytokine levels at enrollment and follow-up. Mann-Whitney U tests were used to compare the change in cytokine level between the two treatment groups (oral and vaginal) before and after therapy. All statistical tests were evaluated at the .05 significance level.

The sample size and power calculation were based on the number of subjects required to detect a 50% difference in interleukin-1ß levels before and after treatment for bacterial vaginosis. Calculations were not based on changes in other cytokine levels because interleukin-6 levels have not been correlated with bacterial vaginosis, and there have been inconsistent reports on interleukin-8 levels in the presence bacterial vaginosis. Calculations were not based on differences in cure rates between the oral and vaginal treatment groups because there is no evidence that there is a significant difference in cure rates between these two treatments. With 80% power at the .05 level of statistical significance to detect a 50% difference in cervical interleukin-1ß levels before and after treatment for bacterial vaginosis, it was determined that a minimum of 36 subjects cured with treatment would be required.

	RESULTS

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During the recruitment period, 406 pregnant women in the outpatient clinic population had bacterial vaginosis. Of these, 279 were ineligible for the study because they did not meet the inclusion criteria. The remaining 127 women were approached for study entry. Sixteen women declined enrollment, and 111 were enrolled. Eight of these were excluded because they did not meet the Gram stain criteria for bacterial vaginosis (n = 3), had Trichomonas vaginalis identified by culture (n = 4), or were lost to follow-up (n = 1). There was insufficient cervical fluid sample for cytokine analysis for one subject, leaving 102 women who made up the evaluable study group. Of these, 52 women (51%) were randomized to the oral metronidazole group and 50 (49%) to the vaginal metronidazole group. For the entire cohort, the median age was 22 years (range 18–39), and the median gestational age at enrollment was 13 weeks (range 8–22). The current Centers for Disease Control and Prevention guidelines state that use of oral metronidazole during the first trimester for therapy is safe.¹³ The median gravidity was 2 (range 1–9), and median parity was 1 (range 0–5). Perfect compliance with therapy was reported by 95 of 102 women (93%). When stratified by treatment group, perfect compliance was reported by 90% and 96% of subjects in the oral and vaginal groups, respectively. Other demographic and behavioral characteristics, stratified by treatment group, are presented in Table 1. The only difference identified between the groups was that there were significantly more women younger than 20 years in the oral metronidazole group and more women between ages 21 and 24 in the vaginal treatment group (P = .01).

	DISCUSSION

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In this study of 102 pregnant women with bacterial vaginosis, cure rates 4 weeks after treatment were equivalent in women treated with oral and vaginal metronidazole and were approximately 70%. Cervical levels of both interleukin-1ß and -6 decreased after treatment and cure in both the oral and vaginal treatment groups. Cervical levels of interleukin-8 also decreased after treatment and cure. Although the levels of cytokines in cervical secretions had a wide range, the use of a paired statistical test, in which women are used as their own controls, comparing baseline results to those after therapy helps to overcome the large person-to-person variability in cytokine levels.

Definitions of cure vary among published trials on treatment of bacterial vaginosis, which leads to difficulty in comparing efficacy between the present study and those studies published previously. In the present study, the US Food and Drug Administration guidance for assessing efficacy was used, and these criteria are more stringent than the traditionally applied criteria.²⁷ Hauth et al⁹ demonstrated resolution of bacterial vaginosis (defined as less than three of four clinical signs and normal flora on Gram stain) in 70% of women 2–4 weeks after treatment with oral metronidazole and erythromycin, and McGregor et al²⁸ published cure rates of 92.5% 2–4 weeks after oral clindamycin use. With the use of topical therapy, cure rates were 85.5% 2 weeks after intravaginal clindamycin cream in a cohort of pregnant women with bacterial vaginosis¹⁶ and 63% 4 weeks after use of intra-vaginal metronidazole gel in a nonpregnant population.²⁹ More contemporary studies in nonpregnant women have documented lower cure rates with the use of intravaginal clindamycin cream or ovules (47.8% and 53.7%, respectively).³⁰ It has been well documented that bacterial vaginosis gradually recurs with longer follow-up in pregnant and nonpregnant women, and rates of cure are dependent on the timing of follow-up evaluation.^15,29

In this study, oral and vaginal metronidazole therapy was compared in a group of pregnant women early in pregnancy. The two treatment modalities were equivalent in their ability to both clear the clinical signs of bacterial vaginosis and restore a Lactobacillus-predominant vaginal flora. This is not surprising because the two regimens are equally efficacious in nonpregnant women.³¹ Study subjects tolerated the medications well, and there was no difference in self-reported compliance rates between the two groups.

Interleukin-1ß is a potent proinflammatory cytokine that is among the first released at the site of infection. It is produced by multiple cell types and is a known regulator of prostaglandin biosynthesis by intrauterine tissue.^32,33 In this study, cervical levels of interleukin-1ß decreased after treatment and cure of bacterial vaginosis in both the oral and vaginal treatment groups. In previous work, interleukin-6 levels have not been found to be correlated with bacterial vaginosis and were not consistently elevated or decreased in women with this vaginal syndrome.^19,20 Interestingly, we found that cervical levels of interleukin-6 also decreased after treatment and cure of bacterial vaginosis in both treatment groups. It is known that interleukin-6 is induced by interleukin-1. If treatment of bacterial vaginosis serves to substantially decrease cervical interleukin-1ß levels, then this might account for the concordant decrease in interleukin-6.

Like interleukin-1ß, interleukin-8 is a proinflammatory cytokine that is produced by several cell types. It has previously been found to be elevated in the presence of bacterial vaginosis, both in women with twin pregnancies between 24 and 34 weeks’ gestation and in infertility patients undergoing in vitro fertilization.^20,22 In the current study, cervical levels of interleukin-8 decreased after treatment and cure of bacterial vaginosis, although this study was not powered to detect a change in interleukin-8 levels. Additionally, the interleukin-8 assays yielded a very wide range of values, which might have precluded the detection of a difference before and after treatment when subjects were stratified by therapy.

Bacterial vaginosis has traditionally been considered a noninflammatory condition, but these findings clearly demonstrate that this condition is associated with inflammatory changes at the cervix. The finding of a decrease in proinflammatory cytokine levels after treatment of bacterial vaginosis and restitution of normal flora suggests that these proinflammatory cytokine changes are directly related to the vaginal flora. The persistence of interleukin-1ß among women who failed therapy might be related to the persistence of bacterial endotoxin in the vagina.

A strength of this clinical trial was its high rate of follow-up. Only one subject was lost, and data were available for all others. Our patient population consisted largely of unmarried black women, which might limit the generalizability of our results. Still, among women in the United States, the prevalence of bacterial vaginosis is highest among this racial group, and there is no evidence that these women respond differently to treatment. The majority of subjects were enrolled in the first trimester, and patients were not reevaluated after the 4 week follow-up visit. Because of this, we have no knowledge of the recurrence rates after successful treatment. The primary goal of this analysis, however, was to compare treatment efficacy and cytokine profiles immediately before and after treatment.

Bacterial vaginosis is a common lower genital tract infection in pregnant women and is associated with adverse outcomes. We have demonstrated that treatment with oral or vaginal metronidazole is equally effective and well tolerated, with cure rates in the range of 70%. Treatment and cure of bacterial vaginosis in pregnancy results both in the normalization of vaginal flora and in a change in the cervical inflammatory cytokine milieu. In assessing the impact of treatment on prematurity prevention, future clinical trials of antibiotic therapy should evaluate both microbiologic and inflammatory end points.

	Footnotes

 
Supported in part by an unrestricted research grant from 3M Pharmaceuticals and by National Institutes of Health grant U01 AI 47785.

The authors thank the outpatient clinic staff at Magee-Womens Hospital for their assistance with recruitment of subjects and Lisa Cosentino for her assistance with the cytokine analyses.

doi:10.1016/S0029-7844(03)00566-0

Received December 26, 2002. Received in revised form April 4, 2003. Accepted April 17, 2003.

	REFERENCES

TOP ABSTRACT MATERIALS AND METHODS RESULTS DISCUSSION REFERENCES

 
1. Hillier SL, Nugent RP, Eschenbach DA, Krohn MA, Gibbs RS, Martin DH, et al. Association between bacterial vaginosis and preterm delivery of a low-birth-weight infant. N Engl J Med 1995;333:1737–42.[Abstract/Free Full Text]

2. Gravett MG, Hammel D, Eschenbach DA, Holmes KK. Preterm labor associated with subclinical amniotic fluid infection and with bacterial vaginosis. Obstet Gynecol 1986;67:229–37.[Medline]

3. Minkoff H, Brunebaum AN, Schwartz RH, Feldman J, Cummings M, Crombleholme W, et al. Risk factors for prematurity and premature rupture of membranes: A prospective study of the vaginal flora in pregnancy. Am J Obstet Gynecol 1984;150:965–72.[Medline]

4. Hillier SL, Martius J, Krohn MA, Kiviat N, Holmes KK, Eschenbach DA. A case-control study of chorioamnionic infection and histologic chorioamnionitis in prematurity. N Engl J Med 1988;319:972–8.[Abstract]

5. Watts DH, Krohn MA, Hillier SL, Eschenbach DA. Bacterial vaginosis as a risk factor for postcesarean endometritis. Obstet Gynecol 1990;75:52–8.[Abstract/Free Full Text]

6. Soper DE, Bump RC, Hunt WG. Bacterial vaginosis and trichomonas vaginitis are risk factors for cuff cellulitis after abdominal hysterectomy. Am J Obstet Gynecol 1990;163: 1016–23.[Medline]

7. Korn AP, Bolan G, Padian N, Ohm-Smith M, Schacter J, Landers DV. Plasma cell endometritis in women with symptomatic bacterial vaginosis. Obstet Gynecol 1995;85: 387–90.[Abstract]

8. Wiesenfeld HC, Hillier SL, Krohn MA, Amortegui AA, Heine RP, Landers DV, et al. Lower genital tract infection and endometritis: Insight into subclinical pelvic inflammatory disease. Obstet Gynecol 2002;100:456–63.[Abstract/Free Full Text]

9. Hauth JC, Goldenberg RL, Andrews WW, DuBard MB, Copper RL. Reduced incidence of preterm delivery with metronidazole and eythromycin in women with bacterial vaginosis. N Engl J Med 1995;333:1732–6.[Abstract/Free Full Text]

10. Morales WJ, Schorr S, Albritton J. Effects of metronidazole in patients with preterm birth in preceding pregnancy and bacterial vaginosis: A placebo-controlled, double-blind study. Am J Obstet Gynecol 1994;171:345–9.[Medline]

11. McDonald HM, O’Loughlin JA, Vigneswaran R, Jolley PT, Harvey JA, Bof A, et al. Impact of metronidazole therapy on preterm birth in women with bacterial vaginosis flora (Gardnerella vaginalis): A randomised, placebo controlled trial. Br J Obstet Gynaecol 1997;104:1391–7.[Medline]

12. Carey JC, Klebanoff MA, Hauth JC, Hillier SL, Thom EA, Ernest JM, et al. Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis. N Engl J Med 2000;342:534–40.[Abstract/Free Full Text]

13. Centers for Disease Control and Prevention. Sexually transmitted diseases treatment guidelines 2002. MMWR Morb Mortal Wkly Rep 2002;51:1–80.[Medline]

14. Kekki M, Kurki T, Pelkonen J, Kurkinen-Raty M, Cacciatore B, Paavonen J. Vaginal clindamycin in preventing preterm birth and peripartum infections in asymptomatic women with bacterial vaginosis: A randomized, controlled trial. Obstet Gynecol 2001;97:643–8.[Abstract/Free Full Text]

15. McGregor JA, French JI, Jones W, Milligan K, McKinney PJ, Pattersen E, et al. Bacterial vaginosis is associated with prematurity and vaginal fluid mucinase and sialidase: Results of a controlled trial of topical clindamycin cream. Am J Obstet Gynecol 1994;170:1048–60.[Medline]

16. Joesoef MR, Hillier SL, Wiknjosastro G, Sumampouw H, Linnan M, Norojono W, et al. Intravaginal clindamycin treatment for bacterial vaginosis: Effects on preterm delivery and low birth weight. Am J Obstet Gynecol 1995;173: 1527–31.[Medline]

17. Vermeulen GM, Bruinse HW. Prophylactic administration of clindamycin 2% vaginal cream to reduce the incidence of spontaneous preterm birth in women with an increased recurrence risk: A randomized placebo-controlled double-blind trial. Br J Obstet Gynaecol 1999;106: 652–7.[Medline]

18. Gomez R, Ghezzi F, Romero R, Munoz H, Tolosa JE, Rojas I. Premature labor and intra-amniotic infection. Clin Perinatol 1995;22:281–342.[Medline]

19. Platz-Christensen JJ, Mattsby-Baltzer I, Thomsen P, Wiqvist N. Endotoxin and interleukin-1 in the cervical mucus and vaginal fluid of pregnant women with bacterial vaginosis. Am J Obstet Gynecol 1993;169:1161–6.[Medline]

20. Mattsby-Baltzer I, Platz-Christensen JJ, Hosseini N, Rosen P. IL-1ß, IL-6, TNF, fetal fibronectin, and endotoxin in the lower genital tract of pregnant women with bacterial vaginosis. Acta Obstet Gynecol Scand 1998;77:701–6.[Medline]

21. Wennerholm U, Holm B, Mattsby-Baltzer I, Nielsen T, Platz-Christensen JJ, Sundell G, et al. Interleukin-1, interleukin-6 and interleukin-8 in cervico/vaginal secretions for screening of preterm birth in twin gestation. Acta Obstet Gynecol Scand 1998;77:508–14.[Medline]

22. Spandorfer SD, Neuer A, Giraldo PC, Rosenwaks Z, Witkin SS. Relationship of abnormal vaginal flora, proinflammatory cytokines and idiopathic infertility in women undergoing IVF. J Reprod Med 2001;46:806–10.[Medline]

23. Nugent RP, Krohn MA, Hillier SL. Reliability of diagnosing bacterial vaginosis is improved by a standardized method of Gram stain interpretation. J Clin Microbiol 1991;29:297–301.[Abstract/Free Full Text]

24. Amsel R, Totten PA, Spiegel CA, Chen KCS, Eschenbach DA, Holmes KK. Nonspecific vaginitis: Diagnostic criteria and microbial and epidemiological associations. Am J Med 1983;74:14–22.[Medline]

25. Gardner HL, Dukes CD. Haemophilus vaginalis vaginitis. Am J Obstet Gynecol 1955;69:962–76.[Medline]

26. Eschenbach DA, Hillier SL, Critchlow C, Stevens C, DeRouen T, Holmes KK. Diagnosis and clinical manifestations of bacterial vaginosis. Am J Obstet Gynecol 1988; 158:819–28.[Medline]

27. US Food and Drug Administration. Guidance for industry. Bacterial vaginosis—developing antimicrobial drugs for treatment. Available at: http://www.fda.gov/cder/guidance/2572dft.pdf. Accessed 2003 April 28.

28. McGregor JA, French JI, Parker R, Draper D, Patterson E, Jones W, et al. Prevention of premature birth by screening and treatment for common genital tract infections: Results of a prospective controlled evaluation. Am J Obstet Gynecol 1995;173:157–67.[Medline]

29. Livengood CH, McGregor JA, Soper DE, Newton E, Thomason JL. Bacterial vaginosis: Efficacy and safety of intravaginal metronidazole treatment. Am J Obstet Gynecol 1994;170:759–64.[Medline]

30. Sobel J, Peipert JF, McGregor JA, Livengood C, Martin M, Robbins J, et al. Efficacy of clindamycin vaginal ovule (3-day treatment) vs. clindamycin vaginal cream (7-day treatment) in bacterial vaginosis. Infect Dis Obstet Gynecol 2001;9:9–15.[Medline]

31. Hanson JM, McGregor JA, Hillier SL, Eschenbach DA, Kreutner AK, Galask RP, et al. Metronidazole for bacterial vaginosis: A comparison of vaginal gel vs. oral therapy. J Reprod Med 2000;45:889–96.[Medline]

32. Dinarello CA, Wolff SM. The role of interleukin-1 in disease. N Engl J Med 1993;328:106–13.[Free Full Text]

33. Romero R, Durum S, Dinarello CA, Oyarzum E, Hobbins JC, Mitchell MD. Interleukin-1 stimulates prostaglandin biosynthesis by human amnion. Prostaglandins 1989;37: 13–22.[Medline]

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