title: A fetal response to chorioamnionitis is associated with early survival after preterm birth.
abstract: OBJECTIVE
  The purpose of this study was to determine, in a large preterm cohort (20-34 completed weeks of gestation), the incidence of histologic chorioamnionitis and the incidence of a histologic fetal response to chorioamnionitis (umbilical vasculitis with or without funisitis) in neonatal survivors (to 28 days) and perinatal deaths.
  
  
  METHODS
  Placental histopathology was reviewed (n=3928 reports). In a subset of this cohort (n=2076 reports), evidence of a histologic fetal response was compared in neonatal survivors and perinatal deaths.
  
  
  RESULTS
  The incidence of histologic chorioamnionitis ranged from 66% at 20 to 24 weeks of gestation (n=261 neonates) to 16% at 34 weeks (n=770 neonates). The overall incidence was 31% (n=3928 neonates). At 25 to 29 weeks of gestation, neonatal survivors had a higher incidence of histologic chorioamnionitis (P=.02; 95% CI, 1.02-1.21). In addition, neonatal survivors had a higher incidence of a histologic fetal response to chorioamnionitis at 25 to 29 weeks of gestation (P=.01; 95%CI, 0.33-0.86) and 30 to 34 weeks of gestation (P=.02; 95%CI, 0.18-0.85).
  
  
  CONCLUSIONS
  Histologic chorioamnionitis is inversely related to gestational age. Both histologic chorioamnionitis and a histologic fetal response to chorioamnionitis were observed to be more common in preterm survivors of the neonatal period.
authors.affiliation: RPA Newborn Care, Royal Prince Alfred Hospital, and the University of Sydney, Sydney, Australia.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Lahra
authors.forename: Heather E
authors.initials: HE
authors.lastname: Jeffery
mesh_terms: D001315:Australia / Q000453:epidemiology; D002821:Chorioamnionitis / Q000150:complications* / Q000453:epidemiology / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007226:Infant Mortality; D007231:Infant, Newborn; D007234:Infant, Premature; D007249:Inflammation / Q000209:etiology; D011247:Pregnancy; D012189:Retrospective Studies; D014470:Umbilical Cord / Q000098:blood supply*; D014657:Vasculitis / Q000453:epidemiology / Q000209:etiology*