title: Acquisition and elimination of bacterial vaginosis during pregnancy: a Danish population-based study.
abstract: OBJECTIVE
  the aim was to examine factors associated with acquisition and elimination of bacterial vaginosis in pregnancy.
  
  
  METHODS
  a group of 229 pregnant women were randomly selected from a population-based prospective cohort study of 2927. They were examined at enrollment (mean gestational weeks 16w+0d) and again in mid-third trimester (mean gestational age 32w+3d).
  
  
  METHODS
  BV (Amsel's clinical criteria), microbiological cultures of the genital tract and questionnaire data.
  
  
  RESULTS
  BV prevalence decreased from 17% in early second trimester to 14% in mid-third trimester due to a tenfold higher elimination rate (39%) than incidence rate (4%). Heavy smokers (>10/d) in early pregnancy were at increased risk (5.3[1.1-25]) for the acquisition of BV during pregnancy, as were women receiving public benefits (4.8[1.0-22]), having a vaginal pH above 4.5(6.3[1.4-29]) or vaginal anaerobe bacteria (18[2.7-122]) at enrollment. A previous use of combined oral contraceptives was preventive for the acquisition of BV (0.2[0.03-0.96]). Elimination of BV in pregnancy tended to be associated with a heavy growth of Lactobacillus(3.2[0.8-13]) at enrollment.
  
  
  CONCLUSIONS
  acquisition of BV during pregnancy is rare and is associated with smoking, while the presence of anaerobe bacteria and a vaginal pH >4.5 are interpreted as steps on a gradual change towards BV. In the same way heavy growth of Lactobacillus spp in early pregnancy may be an indicator of women on the way to eliminate BV.
authors.forename: Ida
authors.initials: I
authors.lastname: Vogel
authors.forename: Poul
authors.initials: P
authors.lastname: Thorsen
authors.forename: Bernard
authors.initials: B
authors.lastname: Jeune
authors.forename: Bo
authors.initials: B
authors.lastname: Jacobsson
authors.forename: Niels
authors.initials: N
authors.lastname: Ebbesen
authors.forename: Magnus
authors.initials: M
authors.lastname: Arpi
authors.forename: Annie
authors.initials: A
authors.lastname: Bremmelgaard
authors.forename: Birger R
authors.initials: BR
authors.lastname: Møller
mesh_terms: D001421:Bacteria, Anaerobic / Q000254:growth & development; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015994:Incidence; D007778:Lactobacillus / Q000254:growth & development; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D015995:Prevalence; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D016585:Vaginosis, Bacterial / Q000175:diagnosis / Q000453:epidemiology / Q000382:microbiology / Q000517:prevention & control