title: Placental pathology suggesting that preeclampsia is more than one disease.
abstract: OBJECTIVE
  Our purpose was to evaluate the placental pathology in women with preeclampsia occurring at varying gestational ages.
  
  
  METHODS
  This was a secondary analysis of a prospective observational study of placentas from prespecified complicated pregnancies routinely submitted for standardized examination. For this study, a database of placental diagnoses from liveborn singleton gestations without major malformations was linked to a computerized obstetric database. The rates of standardized placental findings including vascular (atherosis, infarction) and nonvascular (hyperplasia) changes were evaluated according to gestational age at diagnosis of preeclampsia.
  
  
  RESULTS
  Between Jan. 1, 2001, and Sept. 30, 2007, a total of 7122 women with pregnancies complicated by preeclampsia were delivered at our hospital. Of these, 1210 (17%) had placental examinations. Within this cohort, 209, 355, and 646 women were diagnosed with preeclampsia at gestations of 24(0/67) to 33(6/7), 34(0/7) to 36(6/7), and 37(0/7) weeks or longer, respectively. Placental findings revealed hypoplasia was significantly associated with preeclampsia early in the third trimester, and histological evidence of placental vascular lesions was significantly increased at gestations of 24(0/67) to 33(6/7) weeks (53%) compared with 34% and 26% at 34(0/7) to 36(6/7) and 37 weeks or longer, respectively (P < .001).
  
  
  CONCLUSIONS
  The placentas of women with preeclampsia onset before 34 weeks' gestation were significantly different from those with preeclampsia at term. The former group demonstrated placental findings predominantly consistent with insufficiency because of vascular abnormalities. Such differing placental findings support the hypothesis that preeclampsia is a different disease, depending on the gestational age at diagnosis.
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX. Electronic address: DavidB.Nelson@UTSouthwestern.edu.
authors.forename: David B
authors.initials: DB
authors.lastname: Nelson
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX.
authors.forename: Mandolin S
authors.initials: MS
authors.lastname: Ziadie
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX.
authors.forename: Donald D
authors.initials: DD
authors.lastname: McIntire
authors.affiliation: Department of Pathology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX.
authors.forename: Beverly B
authors.initials: BB
authors.lastname: Rogers
authors.affiliation: Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Leveno
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005865:Gestational Age; D006801:Humans; D010920:Placenta / Q000098:blood supply / Q000473:pathology*; D011225:Pre-Eclampsia / Q000473:pathology*; D011247:Pregnancy; D011248:Pregnancy Complications; D011446:Prospective Studies; D055815:Young Adult
keywords: placental pathology; preeclampsia