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: