title: Increased placental trophoblast inclusions in placenta accreta.
abstract: BACKGROUND
  Trophoblast inclusions (TIs) are often found in placentas of genetically abnormal gestations. Although best documented in placentas from molar pregnancies and chromosomal aneuploidy, TIs are also associated with more subtle genetic abnormalities, and possibly autism. Less than 3% of non-aneuploid, non-accreta placentas have TIs. We hypothesize that placental genetics may play a role in the development of placenta accreta and aim to study TIs as a potential surrogate indicator of abnormal placental genetics.
  
  
  METHODS
  Forty cases of placenta accreta in the third trimester were identified in a search of the medical records at one institution. Forty two third trimester control placentas were identified by a review of consecutively received single gestation placentas with no known genetic abnormalities and no diagnosis of placenta accreta.
  
  
  RESULTS
  Forty percent of cases with placenta accreta demonstrated TIs compared to 2.4% of controls. More invasive placenta accretas (increta and percreta) were more likely to demonstrate TIs than accreta (47% versus 20%). Prior cesarean delivery was more likely in accreta patients than controls (67% versus 9.5%).
  
  
  CONCLUSIONS
  Placenta accreta is thought to be the result of damage to the endometrium predisposing to abnormal decidualization and invasive trophoblast growth into the myometrium. However, the etiology of accreta is incompletely understood with accreta frequently occurring in women without predisposing factors and failing to occur in predisposed patients.
  
  
  CONCLUSIONS
  This study has shown that TIs are present at increased rates in cases of PA. Further studies are needed to discern what underlying pathogenic mechanisms are in common between abnormal placentation and the formation of TIs.
authors.affiliation: Department of Pathology, Montefiore Medical Center, Bronx, NY, USA. Electronic address: esthadler@gmail.com.
authors.forename: E
authors.initials: E
authors.lastname: Adler
authors.affiliation: Department of Obstetrics and Gynecology, North Shore - Long Island Jewish Health System, Glen Cove, NY, USA.
authors.forename: R
authors.initials: R
authors.lastname: Madankumar
authors.affiliation: Department of Obstetrics and Gynecology, Montefiore Medical Center, Bronx, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rosner
authors.affiliation: Department of Pathology, Montefiore Medical Center, Bronx, NY, USA; Department of Pharmaceutical Sciences, St. John's University, Queens, NY, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Reznik
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008875:Middle Aged; D009215:Myometrium / Q000473:pathology*; D010920:Placenta / Q000473:pathology*; D010921:Placenta Accreta / Q000473:pathology*; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D014327:Trophoblasts / Q000473:pathology*; D055815:Young Adult
keywords: Placenta accreta; Trophoblast inclusions