By: Renee Matteucci, MPH; Leonard L. Buckley, MD
Edited by: Diane Pravikoff, RN, PhD, FAAN
Cinahl Information Systems
Cinahl Information Systems
Description & Etiology
Bacterial vaginosis (BV) is a condition in which the normal balance of bacteria in the vagina is disrupted by an overgrowth of anaerobic bacteria and a loss of lactobacilli (i.e., Gram-positive anaerobic bacteria). This overgrowth causes vaginal pH to rise, often resulting in a strong odor and discharge. The bacteria most commonly associated with BV include Prevotella, Bacteroides, Mobiluncus, and mycoplasmas(i.e., a group of bacteria that lack typical cell walls), particularly Mycoplasma hominis, and Gardnerella vaginalis. BV is the most common cause of vaginal discharge and odor in women of childbearing age.
Lactobacilli are important in maintaining a healthy vaginal ecosystem because they contribute to an acidic environment by producing acidulin (i.e., an antibacterial substance), lactacin B (i.e., a bacteriocin, an antibacterial substance), and hydrogen peroxide. A deficiency of lactobacilli leads to changes in the bacterial flora of the vagina, resulting in elevated pH, and increased concentrations of diamines, polyamines, organic acids, and enzymes. It is believed that these enzymes and organic compounds then overcome the host’s immune system, which in pregnant women allows cervicovaginal microorganisms to enter the endometrium and placenta. Although the full impact of BV on placental development and early fetal development is unknown, BV during pregnancy can result in obstetric complications such as spontaneous abortion, preterm labor, preterm birth, low birthweight (i.e., less than 5 pounds), premature rupture of the membranes (PROM), chorioamnionitis (i.e., infection of the amniotic fluid), postpartum and postabortal endometritis, tubal infertility, and post-cesarean wound infection.
BV is not considered a sexually transmitted disease and should be differentiated from other infectious causes of discharge in pregnant women, including gonorrhea, chlamydia, candidiasis, herpes simplex virus, and trichomoniasis, and from non-infective causes of discharge, including tampons, chemical irritation, pelvic inflammatory disease, cancer, and cervical polyps. Antenatal screening is recommended to minimize or eliminate consequences of BV to the fetus and/or neonate, especially if the affected woman is at high risk for preterm labor.
Treatment of BV involves antibiotics (e.g., metronidazole, clindamycin, tinidazole). The CDC recommends a 7-day course of 500 mg oral metronidazole twice a day for 7 days, metronidazole gel, 0.75% 5 g intravaginally once daily for 5 days, or clindamycin cream, 2% 5 g intravaginally at bedtime for 7 days. Tinidazole is administered 1 g once daily for 5 days or 2 g once daily for 2 days. For multiple recurrences, a specialist should be consulted. Antibiotic treatment of asymptomatic pregnant women is controversial; several studies do not suggest a treatment benefit for asymptomatic, average-risk pregnant women and report that maternal use of metronidazole or clindamycin could harm the fetus/neonate. Accurate diagnosis of BV is essential because use of metronidazole and clindamycin among pregnant women who do not have BV may increase risk for preterm delivery. Antibiotic treatment has been found in some studies to reduce the incidence of late miscarriage in high-risk pregnancies (e.g., in women who have had previous preterm deliveries), although the decision to treat is not a universally accepted one among clinicians. Research is ongoing to better understand the risks and benefits of treating BV during pregnancy. Treatment for sex partners is not recommended.
In the United States, BV affects 16% of all pregnant women. The U.S. Centers for Disease Control and Prevention (CDC) estimates there are 1,080,000 cases of BV in pregnant women in the U.S. each year. Up to 67% of pregnant women diagnosed with BV are asymptomatic. BV occurs most frequently in Black women in the U.S. and United Kingdom, abused women, women of childbearing age, HIV-positive women, and women undergoing gynecological surgery. There is a similar prevalence of BV among pregnant and nonpregnant women.
Risk Factors
Risk factors for BV include douching, STDs, multiple sexual partners, early sexual intercourse, and use of intrauterine contraceptive (IUC) devices. Women with BV are at increased risk of infection with HIV, chlamydia, and gonorrhea.
Signs and symptoms in pregnant females are the same as in nonpregnant females and include a thin, homogenous white, clear, or grayish discharge, often with a fishy odor; vaginal burning; and itching.
- Patient History
- Obtain a full pregnancy history, including history of miscarriage or other complications in prior pregnancies; this information may be used in part to guide treatment
- Laboratory Tests That May Be Ordered
- pH colorimetric test or card test will reveal an elevated pH (> 4.5) in BV
- Microscopic examination of vaginal discharge may identify clue cells (i.e., epithelial cells of the vagina that are covered with bacteria)
- Whiff test may reveal a strong, fishy odor after application of potassium hydroxide (KOH) solution
- Gram stain of vaginal discharge diagnoses BV if clue cells are identified; a varied assortment of bacteria may be present, with few lactobacilli
- Maintain Optimum Physiologic Status During Pregnancy and Reduce Risk of Complications
- Assess characteristics of vaginal discharge, and review laboratory/diagnostic test results; immediately report abnormalities and treat, as ordered
- Administer antibiotics as ordered. Monitor treatment efficacy and for adverse effects including nausea, diarrhea, emesis, a metallic taste in the mouth, and hypersensitivity
- Monitor vital signs, intake, output, and for signs of pregnancy complications (e.g., chorioamnionitis, preterm labor); monitor fetal heart rate and rhythm to assess fetal status
- Assess for pain and other discomfort and provide prescribed symptomatic relief
- Request testing, as appropriate, for STDs, especially HIV, chlamydia, and gonorrhea
- Follow facility pre- and postsurgical protocols if patient becomes a candidate for cesarean delivery; reinforce pre- and postsurgical education and ensure completion of facility informed consent documents
- Provide Emotional Support and Educate About Preventing Recurrence
- Assess patient’s anxiety level and coping ability; express empathy, educate, and encourage discussion about BV pathophysiology, potential complications, treatment risks and benefits, strategies that reduce recurrence risk, and individualized prognosis
- Strategies that reduce recurrence risk include avoiding vaginal sex, avoiding douching and the use of feminine hygiene sprays and scented soaps, and completing the medication regimen prescribed for BV even after the symptoms are relieved
- Educate pregnant patients, and especially women at high risk for preterm labor, about keeping the follow-up appointment 1 month after completion of treatment
- BV-related preterm birth may not be prevented by mid-gestational antenatal intravaginal treatment
- Susceptibility to spontaneous preterm birth in pregnant women with BV may be mediated by variants in genes that control the inflammatory response (Gómez et al., 2010)
BV-related complications of premature birth include neonatal sepsis, respiratory distress syndrome, and intraventricular hemorrhage- Intravaginal clindamycin cream is recommended only during the first half of the pregnancy
- The incidence of neonatal sepsis is increased in pregnant women receiving intravaginal clindamycin
- Educate about the necessity of continued medical surveillance during pregnancy and the post-partum period to monitor maternal and fetal/perinatal status, and of taking prenatal vitamins with adequate folate (0.4 mg) daily, as prescribed
- Educate patient to maintain vaginal hygiene by using a clean washcloth each time she cleanses
- Educate about the importance of adherence to the drug regimen to ensure treatment efficacy
- Advise the patient to contact the treating clinician for new or worsening symptoms
1. Centers for Disease Control and Prevention. (2008). Bacterial vaginosis – CDC fact sheet. Retrieved September 21, 2010, from http://www.cdc.gov/std/bv/STDFact-Bacterial-Vaginosis.htm
2. Check treatment options for bacterial vaginosis. (2009). Contraceptive Technology Update, 30(10), 114-116.
3. Denney, J. M., & Culhane, J. F. (2009). Bacterial vaginosis: A problematic infection from both a perinatal and neonatal perspective. Seminars in Fetal & Neonatal Medicine, 14(4), 200-203.
4. Gómez, L. M., Sammel, M. D., Appleby, D. H., Elovitz, M. A., Baldwin, D. A., Jeffcoat, M. K., … Parry, S. (2010). Evidence of a gene-environment interaction that predisposes to spontaneous preterm birth: A role for asymptomatic bacterial vaginosis and DNA variants in genes that control the inflammatory response. American Journal of Obstetrics & Gynecology,202(4), 368.e1-368.e6.
5. Morency, A. M., & Bujold, E. (2007). Treatment of bacterial vaginosis in pregnancy: A new perspective. Journal of Obstetrics and Gynecology Canada: JOGC, 29(2), 115-116.
6. Workowski, K. A., & Berman, S. M. (2006). Sexually transmitted diseases treatment guidelines, 2006. MMWR. Recommendations and Reports: Morbidity and Mortality Weekly Report,55(RR-11), 1-94.
Sara Grose, MSN, RN, PHN, CNL, CLE, Medical Writer, Cinahl Information Systems, Glendale, California
Eliza Schub, BSN, RN, Cinahl Information Systems, Glendale, California
Nursing Practice Council, Glendale Adventist Medical Center, Glendale, California
Original document: 2008 Sep 12
Latest revision: 2010 Sep 24
Published by Cinahl Information Systems. Copyright © 2010, Cinahl Information Systems. All rights reserved. No part of this may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission.
Cinahl Information Systems accepts no liability for advice or information given herein or errors/omissions in the text. It is merely intended as a general informational overview of the subject for the healthcare professional.
Source: Cinahl Information Systems (Glendale, California). 2010 Sep 24 (2p)
Item Number: 5000004398
Cinahl Information Systems accepts no liability for advice or information given herein or errors/omissions in the text. It is merely intended as a general informational overview of the subject for the healthcare professional.
Source: Cinahl Information Systems (Glendale, California). 2010 Sep 24 (2p)
Item Number: 5000004398
