title: Antenatal ultrasound prediction of pulmonary hypoplasia in congenital diaphragmatic hernia: correlation with pathology.
abstract: OBJECTIVE
  To examine the relationship between observed to expected (o/e) lung to head circumference ratio (LHR) and lung-to-body weight ratio (LBWR) in fetuses with congenital diaphragmatic hernia (CDH).
  
  
  METHODS
  All consecutive fetuses with CDH and termination of pregnancy for which a postmortem examination was available, examined at three institutions between 2000 and 2010, were included in the study. Contralateral fetal lung area was measured by two-dimensional ultrasonography using the longest axis method and the o/e-LHR was calculated based on the appropriate normal mean for gestational age (GA). Regression analysis was used to determine the significance of association between the LBWR and the o/e-LHR for left and right-sided cases, and subsequently the predicted LBWR in left-sided CDH was calculated using the regression equation. Regression analysis was used to investigate the effect on the proportional difference between the predicted and observed LBWR of GA at o/e-LHR, time gap between o/e-LHR and LBWR measurement, proportional weight of the ipsilateral compared with total lung weight, presence of associated anomalies and intrathoracic herniation of the liver.
  
  
  RESULTS
  There were 23 fetuses with left-sided and seven fetuses with right-sided CDH. In left-sided CDH, the LBWR and the o/e-LHR correlated significantly, following the linear equation: LBWR = 0.0043 + (0.0134 × o/e-LHR) (r = 0.52, P = 0.012), but this was not the case for right-sided CDH, for which LBWR followed the equation: LBWR = 0.0107 - (0.0014 × o/e-LHR) (r = 0.08, P = 0.862), where o/e-LHR is expressed as percentage. Regression analysis showed that the proportional difference between predicted and observed LBWR in left-sided CDH was significantly and independently associated with GA at o/e-LHR measurement and proportional weight of ipsilateral vs. total lung weight.
  
  
  CONCLUSIONS
  In left-sided CDH, o/e-LHR correlates well with LBWR irrespective of the length of time between o/e-LHR and LBWR measurement, presence of associated anomalies and intrathoracic herniation of the liver. Inconsistencies between the two measurements are mainly attributable to the contribution of the ipsilateral lung to the total lung weight. In right-sided CDH, o/e-LHR does not correlate with LBWR.
authors.affiliation: Department of Obstetrics and Gynecology, Fetal Medicine and Treatment Units, University Hospital Brugmann, Brussels, Belgium. jackjani@hotmail.com
authors.forename: J C
authors.initials: JC
authors.lastname: Jani
authors.forename: A G
authors.initials: AG
authors.lastname: Cordier
authors.forename: J
authors.initials: J
authors.lastname: Martinovic
authors.forename: C F
authors.initials: CF
authors.lastname: Peralta
authors.forename: M V
authors.initials: MV
authors.lastname: Senat
authors.forename: V
authors.initials: V
authors.lastname: Segers
authors.forename: A
authors.initials: A
authors.lastname: Benachi
mesh_terms: D001344:Autopsy; D005260:Female; D005865:Gestational Age; D006257:Head / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D006548:Hernia, Diaphragmatic / Q000000981:diagnostic imaging / Q000473:pathology; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D008168:Lung / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D011237:Predictive Value of Tests; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011651:Pulmonary Artery / Q000002:abnormalities / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D016019:Survival Analysis; D016216:Ultrasonography, Prenatal