Transcript Talk Title

Bacterial 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
Learning 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).
Bacterial 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).
Bacterial 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.
Bacterial 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.
Bacterial Vaginosis: Clinical Diagnosis
1. Amsel criteria:
three of four clincal conditions
•
•
•
•
An elevated vaginal pH (> 4.5).
Amine odor with KOH (whiff test).
Presence of clue cells (20% of cells).
Homogeneous vaginal discharge.
Bacterial Vaginosis: Amsel’s Clinical Diagnosis
• At least 20%
clue cells on wet
mount.
• However,
gardnerella
present 16-42%
women without
BV.
Bacterial Vaginosis: Amsel’s 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
Bacterial Vaginosis: Nugent’s Clinical Diagnosis
Gram stain using Nugent’s criteria:
• High sensitivity and specificity
• Permanent record
• Commonly used in epidemiologic
studies (NICHD maternal-fetal
medicine unit)
Bacterial Vaginosis: Clinical Diagnosis
Gram stain using Nugents criteria:
Lactobacillus
Gardnerella/
Bacteroides
Mobiluncus
Qty
Score Qty
Score Qty
4+
3+
2+
0
1
2
0
1+
2+
0
1
2
1+
3
3+
3
0
4
4+
4
Score
0
0
1+ or 2+ 1
3+ or 4+ 2
Total score: >= 7 indicates BV, 4-6
intermediate stage of BV
Bacterial Vaginosis: Treatment
• Oral Treatment
–Metronidazole (Flagyl)
–Clindamycin (Cleocin)
• Topical Treatment
–Metronidazole 0.75% vaginal cream
(Metrogel)
–Clindamycin 2% vaginal cream
Bacterial Vaginosis in Pregnancy:
Epidemiology
Race
Socioeconomic status
Sexual activity
Vaginal douching
Drug use
Psychosocial stress
Bacterial Vaginosis: Clinical Implications
• Pelvic Inflammatory Disease
• Post-hysterectomy vaginal cuff
cellulitis
• Plasma cell endometritis
Bacterial Vaginosis and Pregnancy:
Clinical Implications
•
•
•
•
•
•
Amniotic fluid infection
Postpartum endometritis
Preterm delivery
Preterm labor
Premature rupture of the membranes
Spontaneous abortion (?)
Bacterial 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: 1.829.4).
– Kurki et al, 1992:
790 pregnant women
21% BV; RR = 6.9 (95%
CI: 2.5-18.8).
Bacterial Vaginosis:
Treatment paradigm in a pregnant population
Pregnant women
Symptomatic
Asymptomatic
High risk
Low risk
Screen
Screen
Screen (?)
Treatment No Treatment
Treatment (?)
No treatment
(Hauth 1995, Morale 1994, McDonald 1997, Carey 2001)
Bacterial Vaginosis and PTD:
Current Research
• Preterm Prediction Study (Goepfert et al,
BV, cervical interleukin-6
concentration, fetal fibronectin level,
short cervical length.
2001):
• Indicators of PTL (Hitti, Hillier et al, 2001) :
Interleukin-6 and -8, neutrophils, BV and
other predictors of amniotic fluid
infection.
Bacterial 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
Spontaneous Abortion Epidemiology
Maternal age
Previous spontaneous abortion
Prenatal cigarette smoking
Prenatal cocaine use
Chromosomal anomalies
BEAR Project:
Bacterial vaginosis
Evaluation
And early
Reproduction
BEAR 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
(N=2200).
BEAR 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.
BEAR Project:
Eligibility 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.
BEAR 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.
BEAR Project:
Baseline 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.
BEAR 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.
BEAR Project:
Follow-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.
BEAR Project: Study Methods
• Case: Women
experiencing a
spontaneous
abortion during
the study period
(20 weeks).
• Control: Pregnant
women maintaining
their pregnancy
through 20 weeks
gestation.
BEAR 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).
BEAR Project: Goals
• Examine the independent
relationship between BV and
spontaneous abortion.
• Assess the separate relationship
between symptomatic and
asymptomatic BV and spontaneous
abortion.
Bacterial 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