title: Left ventricular obstruction with restrictive inter-atrial communication leads to retardation in fetal lung maturation.
abstract: OBJECTIVE
  Intact atrial septum or highly restrictive inter-atrial communication (I/HRAS) combined with either severe aortic stenosis (SAS) or hypoplastic left heart syndrome (HLHS), respectively, is associated with adverse outcome. This study focusses on changes in alveolo-septal lung parenchyma due to increased left atrial pressure.
  
  
  METHODS
  In a retrospective cross-sectional autoptic study, we investigated fetal/neonatal lung specimens of 18 patients with SAS/HLHS with I/HRAS, 11 patients with SAS/HLHS and unrestrictive inter-atrial communications and 18 controls. Pulmonary maturation was investigated by means of morphometric and immunohistochemical analyses.
  
  
  RESULTS
  In a comparison of all three groups, alveolo-capillary membrane maturation was significantly disturbed in I/HRAS fetuses from week 23 of pregnancy on. I/HRAS lungs showed angiomatoid hyper-capillarisation and significantly wider inter-airspace mesenchyme. Differences in width ranged between 34.58 µm (95% CI: 11.41-57.75 µm) and 46.74 µm (95% CI: 13.97-79.50 µm) in the second and third trimesters. In I/HRAS infants with HLHS, inter-airspace mesenchymal diameters steadily normalised with age; however, significant fibroelastosis of alveolar septae developed.
  
  
  CONCLUSIONS
  Fetal lung maturation with respect to alveolo-capillary membrane formation is severely disordered in patients with SAS/HLHS with I/HRAS. Our findings indicate that, from a morphological point of view, timing of fetal invention in fetuses with I/HRAS should be fixed within the second trimester of pregnancy.
authors: Department of Pathology, University Hospital of Bonn, Bonn, Germany.
authors: Diane
authors: D
authors: Goltz
authors: Jean-Marc
authors: JM
authors: Lunkenheimer
authors: Mojtaba
authors: M
authors: Abedini
authors: Ulrike
authors: U
authors: Herberg
authors: Christoph
authors: C
authors: Berg
authors: Ulrich
authors: U
authors: Gembruch
authors: Hans-Peter
authors: HP
authors: Fischer
mesh_terms: D000328:Adult; D001024:Aortic Valve Stenosis / Q000150:complications*; D054087:Atrial Septum; D001344:Autopsy; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000150:complications*; D007231:Infant, Newborn; D008168:Lung / Q000196:embryology / Q000473:pathology; D008171:Lung Diseases / Q000196:embryology / Q000209:etiology / Q000473:pathology*; D011247:Pregnancy; D011650:Pulmonary Alveoli / Q000196:embryology / Q000473:pathology*; D012189:Retrospective Studies; D014694:Ventricular Outflow Obstruction / Q000150:complications*