title: Placental villitis of unknown origin: epidemiologic associations.
abstract: OBJECTIVE
  This study was undertaken to investigate the incidence and associations of placental villitis of unknown origin or etiology (VUE).
  
  
  METHODS
  Five hundred nine placentas from women delivered of small-for-gestational-age infants (SGAP) and 529 placentas from women delivering infants with birth weights appropriate for gestational age (AGAP) were examined prospectively for VUE as part of a population-based case control study of SGA infants at term.
  
  
  RESULTS
  VUE was found in 17.3% of SGAP and 11.7% of AGAP and was an independent risk factor for SGA (adjusted odds ratio 2.35, 95% CI 1.55-3.56). Villitis in conjunction with maternal hypertension increased the risk of SGA substantially (adjusted odds ratio 17.7, 95%CI 3.6-86.9). A study of a wide range of pregnancy-related factors found no significant associations with VUE in AGAP. In contrast, VUE in SGAP had significant associations after multivariate analysis with maternal body mass index, multigravidity, ethnicity, and 1 index of maternal infection.
  
  
  CONCLUSIONS
  VUE is an independent risk factor for SGA at term. Maternal factors influence this association, possibly by modifying a systemic effect on fetal growth of villous inflammation at commonly occurring defects in the maternal-fetal immune barrier.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Auckland, New Zealand.
authors.forename: David M
authors.initials: DM
authors.lastname: Becroft
authors.forename: John M
authors.initials: JM
authors.lastname: Thompson
authors.forename: Edwin A
authors.initials: EA
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D002824:Chorionic Villi / Q000473:pathology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D009520:New Zealand / Q000453:epidemiology; D009775:Obstetrics and Gynecology Department, Hospital / Q000706:statistics & numerical data; D010922:Placenta Diseases / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology / Q000473:pathology; D011247:Pregnancy; D012307:Risk Factors