Major postmortem pulmonary histopathological findings in preterm infants in Ethiopia

Background: Respiratory disorders are the leading cause of death in preterm infants. Postmortem lung histological findings may help to confirm or exclude a clinical diagnosis. This study aims to describe the common postmortem pulmonary histological findings and their potential contributions to preterm neonatal mortality in Ethiopia. Methods: A prospective, multicenter, and cross-sectional clinical study of preterm infants was conducted in five hospitals in three regions of Ethiopia. A total of 4,919 preterm infants were enrolled, and of these, 3,852 were admitted to neonatal intensive care units (NICUs). Within 28 days of postnatal age, 1,109 or 29% of those admitted to the NICU died. Consent was requested from all parents for a complete diagnostic autopsy (CDA) and was obtained in 441 of the preterm neonates who died. Histopathological examination of representative lung tissues was performed. Results: On histopathologic examination of the lungs of these deceased preterm neonates, the major abnormal histological changes observed were hyaline membrane disease (HMD) in 81.6%, pneumonia in 44.7%, pulmonary hemorrhage or diffuse alveolar hemorrhage (DAH) in 39%, and meconium aspiration syndrome (MAS) in 5.9%. A combination of histopathological findings, two or more, were also observed in > 30% of the preterm lungs. Conclusions: HMD was the most common pulmonary finding in extremely and moderately preterm infants. The highly prevalent pneumonia and pulmonary hemorrhage, together with the frequently observed HMD, might have significantly contributed to their deaths. Histopathological findings, beyond confirming a clinical suspicion, can be used as an input in redesigning clinical-radiological parameters to identify respiratory pathologies, particularly pneumonia, in preterm infants.