Treatment of persistent bacterial vaginosis and risk for spontaneous
preterm birth
Yair J. Blumenfeld, MD1, Ivana Marić,
PhD2, David K. Stevenson, MD2,
Ronald S. Gibbs, MD1, Gary M Shaw,
DrPH2
1Department of Obstetrics & Gynecology, Stanford
University School of Medicine, 94305
2Department of Pediatrics, Stanford University School
of Medicine, March of Dimes Prematurity Research Center, Stanford,
California, 94305
Corresponding author:
Yair J. Blumenfeld, MD
Associate Professor
Department of Obstetrics & Gynecology
Stanford University School of Medicine
300 Pasteur Drive, Room H304B
Stanford, California, 94305
yairb@stanford.edu
650-269-4665
Running Title: Treatment of persistent bacterial vaginosis in pregnancy
is associated with a higher risk for spontaneous preterm birth.
Abstract:
Objective:
To determine the association between treatment of persistent BV in
pregnancy and risk for spontaneous preterm birth (sPTB).
Design:
The retrospective data from IBM® MarketScan® Commercial Database was
analyzed.
Setting:
United States outpatient data.
Population or Sample:
Women aged 12–55 years with a singleton gestation.
Methods:
Women were linked to an outpatient medications database and medications
taken during the pregnancy were analyzed. Treatment of BV in pregnancy
was defined as a diagnosis of BV and treatment with Metronidazole and/or
Clindamycin, and persistent treatment of BV was defined as BV in more
than 1 trimester or BV requiring more than 1 antibiotic prescription.
Odds ratios were calculated comparing sPTB in those with BV and
persistent BV to women without BV in pregnancy. Survival analysis using
Kaplan-Meier curves for the gestational age at delivery was also
performed.
Main outcome measures:
sPTB
Results:
Among a cohort of 2,538,606 women, 216,611 had an associated ICD-9 or
ICD-10 code for diagnosis of BV alone, and 63,817 had BV and were
treated with either metronidazole and/or clindamycin. The sPTB rate
among women treated with BV was 7.5% compared with 5.7% for women
without BV who did not receive antibiotics. Relative to those without BV
in pregnancy, odds ratios for sPTB were highest in those treated for BV
in both the first and second trimester (1.66 [95% CI 1.52, 1.81])
or those with 3 or more prescriptions in pregnancy (1.48 [95% CI
1.35, 1.63].
Conclusions:
Treatment of persistent BV is associated with increased sPTB risk.
Keywords: Bacterial Vaginosis, spontaneous preterm birth, recurrent
Introduction:
Bacterial vaginosis (BV) results from a change in the normal microbial
environment of the vagina, with a lack of hydrogen peroxide-producing
lactobacilli and an overgrowth of facultative anaerobic organisms
including Gardnerella vaginalis, Bacteroides species, Mycoplasma
hominis, Peptostreptococcus species, and other
species.1 Approximately 20-50% of reproductive age
women will experience an episode of BV, and 6-19% will have an episode
of BV during pregnancy.2,3 An underlying infectious or
inflammatory etiology is one of the suspected leading contributors to
spontaneous preterm birth (sPTB), and the association between BV and
sPTB has been previously described in multiple
studies.4 Despite this known association, screening
and treatment of BV in pregnancy as a means of reducing sPTB remains
controversial. A recent US Preventative Task Force addressing screening
for BV to prevent preterm delivery “recommended against screening for
bacterial vaginosis in pregnant persons not at increased risk for
preterm delivery.”5
Although for most women an episode of BV will resolve without any
difficulty or long term sequalae, persistent BV, defined as BV that
recurs or fails to improve after an initial antibiotic course,
complicates 20-75% of all cases.6 Persistent BV has
been linked with a variety of adverse effects including discomfort and
pain, negative emotional, sexual, and social effects.7While the association between first trimester BV with sPTB has been
previously described, there is a paucity of data about the association
between treatment of persistent BV during pregnancy and sPTB. Our aim
was to determine whether treatment of persistent BV is associated with a
higher risk for sPTB.
Methods: