title: Are early and late preeclampsia distinct subclasses of the disease--what does the placenta reveal?
abstract: OBJECTIVE
  To compare histopathological differences in placentas from early- and late-onset preeclampsia, as well as late-onset preeclampsia and normal term deliveries.
  
  
  METHODS
  This prospective study was performed at Tygerberg Hospital, a secondary and tertiary referral center in South Africa. Placentas from 100 women, 25 each with early and late-onset preeclampsia, and an equal number of controls matched for gestational age, underwent routine preparation and were evaluated independently by two pathologists in a strictly predetermined, standardized manner.
  
  
  RESULTS
  Compared to late preeclampsia, placentas in the early preeclampsia group were smaller (p < 0.01), had more infarction (odds ratio [OR] = 4.03, 95% confidence interval [CI] = 1.2-13.5) and inappropriate maturation (OR = 16.62, 95% CI = 4.1-68.0). Placentas from the late-onset preeclampsia group showed increased decidual arteriopathy (OR = 5.09, 95% CI = 1.45-17.92) and abruptio placentae (OR = 5.41, 95% CI = 1.01-28.79) compared to controls.
  
  
  CONCLUSIONS
  The early- and late-onset preeclampsia placentas showed clear histopathological differences, whereas late-onset preeclampsia and normal term placentas differed less. These findings support the contention that early- and late-onset preeclampsia are different subclasses of disease.
authors.affiliation: Department of Obstetrics and Gynaecology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
authors.forename: J L
authors.initials: JL
authors.lastname: van der Merwe
authors.forename: D R
authors.initials: DR
authors.lastname: Hall
authors.forename: C
authors.initials: C
authors.lastname: Wright
authors.forename: P
authors.initials: P
authors.lastname: Schubert
authors.forename: D
authors.initials: D
authors.lastname: Grové
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D016017:Odds Ratio; D010920:Placenta / Q000473:pathology*; D011225:Pre-Eclampsia / Q000145:classification* / Q000473:pathology*; D011247:Pregnancy