Title: Bacterial Vaginosis and Pregnancy: Clinical Overview and Public Health Implications
1Bacterial Vaginosis and Pregnancy Clinical
Overview and Public Health Implications
- Deborah B. Nelson, Ph.D.
- Assistant Professor
- Center for Clinical Epidemiology and
Biostatistics - University of Pennsylvania School of Medicine
http//www.med.upenn.edu/crrwh/Nelson.html
2Learning Objectives
- Review the Prevalence, Identification, and
Treatment of Bacterial Vaginosis (BV) - Describe the Epidemiology and Consequences of
Bacterial Vaginosis in Pregnancy - Discuss Current Research Findings
- Present the BEAR Project Hypothesis, Specific
Aims and Methodology -
Nelson DB, Macones GA. Bacterial Vaginosis in
Pregnancy Current Findings and Future
Directions. Epidemiologic Reviews 2002 (24
102-108).
3Bacterial Vaginosis Clinical Background
- BV is the most frequent cause of vaginal
discharge - 3 million cases of BV 800,000 cases among
pregnant women annually (Goldman Hatch 2000). - Prevalence of BV 25-60 among nonpregnant
women 10-35 among pregnant women (Goldman
Hatch 2000).
4Bacterial Vaginosis Microbiology
- The normal vagina is an acidic environment
inhabited primarily by hydrogen-producing
lactobacilli - There is some change in the microbiological flora
of the vagina (due to environmental, behavioral,
or hormonal factors) - BV is characterized by a reduced number of
lactobacilli and an overgrowth of gram negative,
anaerobic bacteria.
5Bacterial Vaginosis Microbiology
- Anaerobic organisms in BV include Mycoplasma
hominis, Bacteroides spp., Mobiluncus spp.,
Gardnerella vaginalis. - Increase in polyamines resulting in the
characteristic odor of BV and the increase in
epithelial cell exfoliation.
6Bacterial Vaginosis Clinical Diagnosis
- Amsel criteria
- three of four clincal conditions
-
- An elevated vaginal pH (gt 4.5).
- Amine odor with KOH (whiff test).
- Presence of clue cells (20 of cells).
- Homogeneous vaginal discharge.
7Bacterial Vaginosis Amsels Clinical Diagnosis
- At least 20 clue cells on wet mount.
- However, gardnerella present 16-42 women without
BV.
8Bacterial Vaginosis Amsels Clinical Diagnosis
- Assessment of vaginal pH lacks specificity
- Conduct of Whiff test is subjective and lacks
sensitivity - Identification of clue cells subjected to skill
and interpretation of the microscopist
9Bacterial Vaginosis Nugents Clinical Diagnosis
- Gram stain using Nugents criteria
- High sensitivity and specificity
- Permanent record
- Commonly used in epidemiologic studies (NICHD
maternal-fetal medicine unit)
10Bacterial Vaginosis Clinical Diagnosis
- Gram stain using Nugents criteria
Gardnerella/ Bacteroides
Lactobacillus
Mobiluncus
Total score gt 7 indicates BV, 4-6 intermediate
stage of BV
11Bacterial Vaginosis Treatment
- Oral Treatment
- Metronidazole (Flagyl)
- Clindamycin (Cleocin)
- Topical Treatment
- Metronidazole 0.75 vaginal cream (Metrogel)
- Clindamycin 2 vaginal cream
12Bacterial Vaginosis in Pregnancy Epidemiology
- Race
- Socioeconomic status
- Sexual activity
- Vaginal douching
- Drug use
- Psychosocial stress
13Bacterial Vaginosis Clinical Implications
- Pelvic Inflammatory Disease
- Post-hysterectomy vaginal cuff cellulitis
- Plasma cell endometritis
14Bacterial Vaginosis and Pregnancy Clinical
Implications
- Amniotic fluid infection
- Postpartum endometritis
- Preterm delivery
- Preterm labor
- Premature rupture of the membranes
- Spontaneous abortion (?)
15Bacterial Vaginosis and Pregnancy Current
Research
Preterm Delivery
- Hillier et al, 1995
- 10,000 pregnant women
- 16 BV RR 1.4 (95 CI 1.1-1.8).
- Gratacos et al, 1998
- 635 pregnant women
- 20 BV RR 3.1 (95 CI 1.8-29.4).
- Kurki et al, 1992
- 790 pregnant women
- 21 BV RR 6.9 (95 CI 2.5-18.8).
16Bacterial Vaginosis Treatment paradigm in a
pregnant population
Symptomatic
Asymptomatic
High risk
Low risk
Screen
Screen
Screen (?)
Treatment
No Treatment
Treatment (?)
No treatment
(Hauth 1995, Morale 1994, McDonald 1997, Carey
2001)
17Bacterial Vaginosis and PTD Current Research
- Preterm Prediction Study (Goepfert et al, 2001)
BV, cervical interleukin-6 concentration, fetal
fibronectin level, short cervical length. - Indicators of PTL (Hitti, Hillier et al, 2001)
Interleukin-6 and -8, neutrophils, BV and other
predictors of amniotic fluid infection.
18Bacterial Vaginosis and Spontaneous Abortion
Current Research
- Sub-analyses
- RR 5.5 (95 CI 2.3 - 13.3) Hay et al, 1994
- RR 3.2 (95 CI 1.4 - 6.9) McGregor et al 1995
- High risk populations
- RR 2.67 (95 CI 1.26 - 5.63) Ralph et al 1999
19Spontaneous Abortion Epidemiology
Maternal age
Previous spontaneous abortion
Prenatal cigarette smoking
Prenatal cocaine use
Chromosomal anomalies
20Bacterial vaginosis Evaluation And early
Reproduction
BEAR Project
21BEAR Project Study Design
- Four year NICHD-funded study.
- Prospective cohort enrolling women seeking
prenatal care. - Exposure Bacterial Vaginosis.
- Outcome Spontaneous Abortion.
- 30 month data collection period (N2200).
-
22BEAR Project Specific Aims
- Aim 1 Among women seeking prenatal care at urban
obstetric clinics, characterize the prevalence
and predictors of BV. - Aim 2 Evaluate whether BV during pregnancy is an
important, independent predictor of SAB.
23BEAR ProjectEligibility Criteria
- OB patient at their first prenatal care visit
seen at the Gates clinic or PTP. - 12.6 weeks gestation or earlier based on last
menstrual period. - Resident of Philadelphia.
- Single, intrauterine pregnancy.
24BEAR Project Study Methods
- Baseline data collection (Nurse Coordinators)
- Enroll women and obtain informed consent.
- Collect vaginal swabs for all eligible women
(regardless of symptoms). - Obtain urine sample.
- Administer 15 minute questionnaire.
25BEAR ProjectBaseline Questionnaire
- Risk factors for BV race, prior and current
sexual activity, douching, drug use, psychosocial
stress measures. - Risk factors for SAB age, prior pregnancy
information, drug use, vaginal bleeding.
26BEAR Project Study Methods
- Follow-up data collection (Follow-up Coordinator)
- Conduct follow-up telephone interviews.
- Medical confirmation of outcomes through medical
record review. - Classify women as eligible and either a case or
pregnant control.
27BEAR ProjectFollow-up Questionnaire
- Determine pregnancy status at 20 weeks gestation.
- Identify subsequent diagnoses of BV and
compliance with medical therapy. - Measure other risk factors for SAB.
28BEAR Project Study Methods
- Control Pregnant women maintaining their
pregnancy through 20 weeks gestation.
- Case Women experiencing a spontaneous abortion
during the study period (20 weeks).
29BEAR Project Goals
- Determine the prevalence of symptomatic and
asymptomatic BV among women in first trimester of
pregnancy. - Identify predictors of BV in the first trimester
(ie. stress, douching, prior pregnancy outcomes).
30BEAR Project Goals
- Examine the independent relationship between BV
and spontaneous abortion. - Assess the separate relationship between
symptomatic and asymptomatic BV and spontaneous
abortion.
31Bacterial Vaginosis and Pregnancy Clinical
Implications and Current Research
- Deborah B. Nelson, Ph.D.
- Assistant Professor
- Center for Clinical Epidemiology and
Biostatistics - University of Pennsylvania School of Medicine