title: Histological characteristics of singleton placentas delivered before the 28th week of gestation.
abstract: OBJECTIVE
  The placenta is a record of the fetal environment and its examination may provide information about the baby's subsequent growth and development. We describe the histological characteristics of 947 singleton placentas from infants born between 23 and 27 weeks gestation.
  
  
  METHODS
  Consent was obtained from mothers who delivered before 28 weeks (clinical estimate). We evaluated the gross and histopathological features of the placenta and assessed pair-wise correlations between variables.
  
  
  RESULTS
  Lesions of uteroplacental circulation (abruption, extensive infarction or thrombosis, marked basal or perivillous fibrin deposition, increased syncytial knots) were inversely related to those associated with inflammation of the membranes and cord. Earlier age favoured inflammatory variables, while older age favoured characteristics attributed to impaired blood flow. We observed inflammation of the chorionic plate in 43%, the cord in 19%, and of chorionic plate vessels in 30%. Of the placentas with umbilical cord inflammation, 8% had no inflammation of the chorionic plate.
  
  
  CONCLUSIONS
  This study population is unique in its size and recruitment by gestational age rather than birth weight. Inflammation occurred frequently, but not in placentas that had characteristics of vasculopathy. The prevalence of inflammation decreased with increasing gestational age, while vasculopathy increased. Funisitis need not be accompanied by chorionic inflammation.
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center, Boston, Massachusetts 02118, USA. jlhecht@bidmic.harvard.edu
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Hecht
authors.forename: Elizabeth N
authors.initials: EN
authors.lastname: Allred
authors.forename: Harvey J
authors.initials: HJ
authors.lastname: Kliman
authors.forename: Eduardo
authors.initials: E
authors.lastname: Zambrano
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Doss
authors.forename: Aliya
authors.initials: A
authors.lastname: Husain
authors.forename: Solveig M V
authors.initials: SM
authors.lastname: Pflueger
authors.forename: Chung-Ho
authors.initials: CH
authors.lastname: Chang
authors.forename: Chad A
authors.initials: CA
authors.lastname: Livasy
authors.forename: Drucilla
authors.initials: D
authors.lastname: Roberts
authors.forename: Ina
authors.initials: I
authors.lastname: Bhan
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Ross
authors.forename: Patricia Kaman
authors.initials: PK
authors.lastname: Senagore
authors.forename: Alan
authors.initials: A
authors.lastname: Leviton
mesh_terms: D000328:Adult; D002821:Chorioamnionitis / Q000473:pathology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D009929:Organ Size; D010920:Placenta / Q000473:pathology*; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D047928:Premature Birth