title: Abnormal spiral artery remodelling in the decidual segment during pregnancy: from histology to clinical correlation.
abstract: BACKGROUND
  Modification of the spiral arteries with loss of the muscular vascular wall, invaded by the trophoblasts, represents the goal of the physiological vascular adaptation during human implantation. When physiological vascular changes do not occur, an unfavourable evolution of gestation may develop as suggested by uterine biopsies studies.
  
  
  OBJECTIVE
  To evaluate the prevalence of the abnormal spiral arteries modification (ASAM) through the routine examination of placentas, to identify maternal predisposing factors and to examine the correlations between the histological lesion and pregnancy outcome.
  
  
  METHODS
  1534 consecutive singleton pregnancies were retrospectively analysed. An extensive histological and clinical investigation was performed.
  
  
  RESULTS
  ASAM was present in 5.8% pregnancies. When compared with cases without ASAM, cases with ASAM exhibited a higher prevalence of pre-eclampsia (10% vs 2%), placental abruption (5.5% vs 0.3%), preterm premature rupture of membranes (7% vs 1.3%) and intrauterine fetal death (18% vs 2.2%). Multivariate analysis showed that the maternal body mass index represents the major maternal pregestational factor that can influence the prevalence of ASAM (OR=1.8, 95% CI 1.1 to 3 in cases with BMI>30 kg/m(2)).
  
  
  CONCLUSIONS
  The abnormal modification of the decidual segment of the spiral arteries is identifiable at the time of the conventional histopathological placental evaluation and is associated with adverse pregnancy outcome. The identification of the cause of the unfavourable evolution of pregnancy is fundamental for parents, both for counselling and for prevention; the identification of ASAM in such pregnancies might provide additional valuable information.
authors.affiliation: Unit of Human Pathology, Department of Medicine, Surgery and Dentistry, San Paolo Hospital Medical School, University of Milano, Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Avagliano
authors.forename: Gaetano Pietro
authors.initials: GP
authors.lastname: Bulfamante
authors.forename: Alberto
authors.initials: A
authors.lastname: Morabito
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Marconi
mesh_terms: D000328:Adult; D001158:Arteries / Q000473:pathology; D003656:Decidua / Q000098:blood supply*; D005260:Female; D005313:Fetal Death / Q000473:pathology; D005317:Fetal Growth Retardation / Q000473:pathology; D005865:Gestational Age; D006801:Humans; D010920:Placenta / Q000098:blood supply*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000473:pathology*; D011256:Pregnancy Outcome; D012189:Retrospective Studies