Alveolar capillary dysplasia with misalignment of pulmonary veins in neonates: a multicenter cohort study

BACKGROUND: Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare developmental lung disorder associated with high neonatal mortality. We aimed to describe the epidemiology, resource utilization, and outcomes of neonates with ACD/MPV. METHODS: Retrospective observational study using the Pediatric Health Information System database. ICD-10 diagnosis codes were used to identify neonates hospitalized with ACD/MPV between 2016 and 2025. Demographic characteristics, associated congenital anomalies, resource utilization, length of stay, and mortality were analyzed. RESULTS: We identified 58 neonates with ACD/MPV during the study period. The demographic distribution includes 51.7% female sex, 60.3% Whites, and 28.4% Hispanics or Latinos. Median gestational age was 38 weeks with a birthweight of 2,883 grams. Cytogenetic testing was documented in 43.1% and surgical tissue biopsy in 53.3% of the neonates. Congenital anomalies were present in 91%, with cardiovascular malformations predominating. Invasive mechanical ventilation (IMV) was used in 93.1%, and extracorporeal membrane oxygenation (ECMO) in 63.8%. ECMO utilization was more common among non-survivors (72.0 vs. 12.5%). Mortality was 86.2%. CONCLUSION: ACD/MPV is a rare neonatal disorder characterized by high mortality and substantial resource utilization. Congenital malformations are frequent, with cardiovascular anomalies predominating. ACD/MPV should be considered in neonates with refractory pulmonary hypertension. IMPACT: This is the largest multicenter study in the U.S to date exploring the epidemiology, resource utilization, and outcomes of neonates with alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV). ACD/MPV is a rare neonatal disorder and carries a very high mortality (86%) despite advanced therapies. ACD/MPV is frequently associated with congenital malformations, which were present in over 91% of the cases, with cardiovascular anomalies predominating. ACD/MPV should be suspected in neonates with prolonged or refractory pulmonary hypertension, and early diagnostic evaluation, like genetic testing or lung biopsy, should be conducted to avoid prolonged futile interventions.