title: Postmortem lung volume/body weight standards for term and preterm infants.
abstract: Assessment of lung growth is a critical component of the perinatal autopsy. Increased lung liquid content may lead to overestimation of lung growth based on (wet) lung weight. In contrast, lung volume is not influenced by intraalveolar lung liquid. Our aim was to establish age-specific reference values for postmortem lung volume/BW in preterm and term infants. We performed a retrospective analysis of fetuses/infants (16-41 weeks' gestation) without (N = 134) or with (N = 79) risk factors for pulmonary hypoplasia. Lungs were inflated at standardized pressure and volumes determined by water immersion method. Lung volume increased 11-fold between 16 and 41 weeks' gestation, concomitant with a 16-fold increase in BW. Mean lung volume/BW remained constant at 33-34 ml/kg between 16 and 31 weeks' gestation and decreased to 23.4 ml/kg at term. Lung volume/BW of infants with severe risk factors (renal anomalies, diaphragmatic hernia) was significantly lower than age-matched standards. In this group, all fetuses/infants diagnosed as having lung hypoplasia by lung volume/BW also had lung hypoplasia LW/BW standards. However, in infants with "softer" risk factors (rupture of membranes, chromosomal anomalies), 5/26 cases diagnosed with lung hypoplasia based on lung volume/BW had normal LW/BW ratios. In these discrepant cases, lung sections showed significant inflammation and edema, likely accounting for increased wet lung weight. In conclusion, we determined age-specific lung volume/BW reference values for preterm and term infants. In selected situations assessment of lung volume/BW may represent a useful complementary tool to LW/BW for postmortem evaluation of lung size.
authors.affiliation: Department of Pathology, Alpert Medical School of Brown University, Providence, Rhode Island; Department of Pathology and Laboratory Medicine, Women and Infants Hospital, Alpert Medical School of Brown University, Providence, Rhode Island.
authors.forename: Monique E
authors.initials: ME
authors.lastname: De Paepe
authors.forename: Svetlana
authors.initials: S
authors.lastname: Shapiro
authors.forename: Katrine
authors.initials: K
authors.lastname: Hansen
authors.forename: Füsun
authors.initials: F
authors.lastname: Gündoğan
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis; D001344:Autopsy; D001835:Body Weight; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development*; D008168:Lung / Q000002:abnormalities / Q000254:growth & development; D008171:Lung Diseases / Q000175:diagnosis; D008176:Lung Volume Measurements; D012016:Reference Values; D012189:Retrospective Studies
keywords: congenital diaphragmatic hernia; lung growth; lung hypoplasia; oligohydramnios; rupture of membranes