title: Effect of antibiotic exposure on Nugent score among pregnant women with and without bacterial vaginosis.
abstract: OBJECTIVE
  To evaluate whether vaginal flora is altered by antibiotic exposure and associated with a risk of preterm birth, particularly among women with initially normal vaginal flora.
  
  
  METHODS
  This was a secondary analysis of a randomized trial of metronidazole and erythromycin for the prevention of preterm birth among women with a positive fetal fibronectin test. Vaginal swabs for Nugent Gram stain score were collected for classification of bacterial vaginosis before and after antibiotic exposure and read at a central laboratory. Change in Nugent score was assessed for women with (score 7 or higher) or without (score lower than 7) bacterial vaginosis. Linear regression analysis evaluated whether change in Nugent score was associated with preterm birth.
  
  
  RESULTS
  Two hundred women without and 69 women with bacterial vaginosis had Gram stain performed before and after antibiotic therapy. Median Nugent score for all women declined from 4.0 to 2.0 after antibiotic therapy (P<.001). Nugent score declined both for those without (from 2.0 to 1.5, P=.11) and, more dramatically, those with bacterial vaginosis (from 8.0 to 3.0, P<.01). The components of the Nugent score that were affected by antibiotic exposure were similar among women with and without bacterial vaginosis. Antibiotic exposure and the change in Nugent score were unrelated to preterm birth among bacterial vaginosis-negative women.
  
  
  CONCLUSIONS
  Antibiotic exposure is not associated with preterm birth and does not worsen Nugent score among women with normal vaginal flora and positive fetal fibronectin.
  
  
  METHODS
  II.
authors.affiliation: From the Department of Obstetrics and Gynecology of Brown University, Providence, Rhode Island; the University of Alabama at Birmingham, Birmingham Alabama; the University of Texas at San Antonio, San Antonio, Texas; the University of Cincinnati, Cincinnati, Ohio; The Ohio State University, Columbus, Ohio; Thomas Jefferson University, Philadelphia, Pennsylvania; the University of Utah, Salt Lake City, Utah; the University of Pittsburgh, Pittsburgh, Pennsylvania; the University of Miami, Miami, Florida; and The George Washington University Biostatistics Center, Washington, DC.
authors.forename: Brenna
authors.initials: B
authors.lastname: Anderson
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.forename: William W
authors.initials: WW
authors.lastname: Andrews
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Dudley
authors.forename: Baha
authors.initials: B
authors.lastname: Sibai
authors.forename: Jay D
authors.initials: JD
authors.lastname: Iams
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Wapner
authors.forename: Michael W
authors.initials: MW
authors.lastname: Varner
authors.forename: Steve N
authors.initials: SN
authors.lastname: Caritis
authors.forename: Mary Jo
authors.initials: MJ
authors.lastname: O'Sullivan
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D015992:Body Mass Index; D016001:Confidence Intervals; D004311:Double-Blind Method; D005260:Female; D005840:Gentian Violet; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D016015:Logistic Models; D008423:Maternal Age; D015999:Multivariate Analysis; D016017:Odds Ratio; D010619:Phenazines; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000188:drug therapy* / Q000382:microbiology; D011256:Pregnancy Outcome; D012016:Reference Values; D018570:Risk Assessment; D014621:Vagina / Q000382:microbiology*; D016585:Vaginosis, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; C035863:Gram's stain; D010619:Phenazines; D005840:Gentian Violet