title: Impact of interconception antibiotics on the endometrial microbial flora.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the impact of an interconception antibiotic regimen on endometrial microbial flora and histologic type.
  
  
  METHODS
  This was a secondary analysis of a double-blind randomized placebo-controlled trial of prophylactic metronidazole plus azithromycin that was given to 241 women (antibiotics, 118 women; placebo, 123 women) with a previous preterm delivery to prevent recurrent preterm delivery. Endometrial cultures and histologic types were obtained at randomization and 2 weeks after treatment. The prevalence of either the new acquisition or the resolution of individual microbes, categories of microbes, and plasma cell endometritis were compared by chi-square or Fishers' exact tests.
  
  
  RESULTS
  Overall, antibiotics were associated with lower acquisition and higher resolution of microbes. Of women without Gardnerella at baseline, 14% of the women who received antibiotics vs 34% of the women who received placebo had positive endometrial culture for the organism after treatment (P < .05); of those women with G. vaginalis at baseline, 57% of the women who received antibiotics vs 33% of the women who received placebo (P < .05) had a negative follow-up culture. Other gram-negative rods, especially aerobes in general, manifested similar patterns. The impact on anaerobes and plasma cell endometritis was not definitive, but there was a trend toward the increased resolution of the former (77% vs 55%) and reduced acquisition of the latter (28% vs 50%).
  
  
  CONCLUSIONS
  The antibiotic regimen prevented the acquisition and promoted the resolution, but not the eradication, of gram-negative rods such as G. vaginalis and the aerobic subcategory.
authors.affiliation: Center for Women's Reproductive Health, Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA.
authors.forename: Alan T N
authors.initials: AT
authors.lastname: Tita
authors.forename: Suzanne P
authors.initials: SP
authors.lastname: Cliver
authors.forename: Alice R
authors.initials: AR
authors.lastname: Goepfert
authors.forename: Michael
authors.initials: M
authors.lastname: Conner
authors.forename: Robert L
authors.initials: RL
authors.lastname: Goldenberg
authors.forename: John C
authors.initials: JC
authors.lastname: Hauth
authors.forename: William W
authors.initials: WW
authors.lastname: Andrews
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D004717:Endometrium / Q000033:anatomy & histology* / Q000187:drug effects / Q000382:microbiology*; D005260:Female; D006801:Humans; D008795:Metronidazole / Q000494:pharmacology*; D016742:Preconception Care
chemical_list: D000890:Anti-Infective Agents; D008795:Metronidazole; D017963:Azithromycin