title: Association between bacterial vaginosis or chlamydial infection and miscarriage before 16 weeks' gestation: prospective community based cohort study.
abstract: OBJECTIVE
  To assess whether bacterial vaginosis or chlamydial infection before 10 weeks' gestation is associated with miscarriage before 16 weeks.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  32 general practices and five family planning clinics in south London.
  
  
  METHODS
  1216 pregnant women, mean age 31, presenting before 10 weeks' gestation.
  
  
  METHODS
  Prevalence of miscarriage before 16 weeks' gestation.
  
  
  RESULTS
  121 of 1214 women (10.0%, 95% confidence interval 8.3% to 11.7%) miscarried before 16 weeks. 174 of 1201 women (14.5%, 12.5% to 16.5%) had bacterial vaginosis. Compared with women who were negative for bacterial vaginosis those who were positive had a relative risk of miscarriage before 16 weeks' gestation of 1.2 (0.7 to 1.9). Bacterial vaginosis was, however, associated with miscarriage in the second trimester at 13-15 weeks (3.5, 1.2 to 10.3). Only 29 women (2.4%, 1.5% to 3.3%) had chlamydial infection, of whom one miscarried (0.32, 0.04 to 2.30).
  
  
  CONCLUSIONS
  Bacterial vaginosis is not strongly predictive of early miscarriage but may be a predictor after 13 weeks' gestation. The prevalence of Chlamydia was too low to assess the risk, but it is unlikely to be a major risk factor in pregnant women.
authors.affiliation: Department of General Practice and Primary Care, St George's Hospital Medical School, London SW17 0RE. oakeshot@sghms.ac.uk
authors.forename: Pippa
authors.initials: P
authors.lastname: Oakeshott
authors.forename: Phillip
authors.initials: P
authors.lastname: Hay
authors.forename: Sima
authors.initials: S
authors.lastname: Hay
authors.forename: Frances
authors.initials: F
authors.lastname: Steinke
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rink
authors.forename: Sally
authors.initials: S
authors.lastname: Kerry
mesh_terms: D000022:Abortion, Spontaneous / Q000453:epidemiology / Q000382:microbiology*; D000293:Adolescent; D000328:Adult; D002690:Chlamydia Infections / Q000150:complications* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008131:London / Q000453:epidemiology; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000382:microbiology*; D011261:Pregnancy Trimester, First; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D016585:Vaginosis, Bacterial / Q000150:complications* / Q000453:epidemiology