Postmortem lung volume/body weight standards for term and preterm infants.

Area of Science:

• Perinatal Pathology
• Pediatric Autopsy
• Fetal Development

Background:

• Accurate assessment of lung growth is crucial in perinatal autopsies.
• Lung weight can be overestimated due to increased lung fluid content.
• Lung volume is a more reliable indicator, unaffected by intra-alveolar fluid.

Purpose of the Study:

• To establish age-specific reference values for postmortem lung volume relative to body weight (BW) in preterm and term infants.
• To evaluate the utility of lung volume/BW in diagnosing pulmonary hypoplasia.

Main Methods:

• Retrospective analysis of 213 fetuses and infants (16-41 weeks gestation).
• Lungs were inflated at standardized pressure; volumes measured by water immersion.
• Comparison of lung volume/BW and lung weight/BW (LW/BW) with established standards.

Main Results:

• Lung volume increased 11-fold and BW 16-fold between 16 and 41 weeks gestation.
• Mean lung volume/BW remained stable until 31 weeks, then decreased to term.
• Significantly lower lung volume/BW observed in infants with severe risk factors for pulmonary hypoplasia.
• Lung volume/BW identified cases with normal LW/BW but inflammation/edema, suggesting hypoplasia.

Conclusions:

• Age-specific reference values for postmortem lung volume/BW in infants were determined.
• Lung volume/BW serves as a valuable complementary tool to LW/BW for evaluating lung size, especially in cases with suspected inflammation or edema.