Prenatal and Perinatal Outcomes in Fetuses With Macrocystic Congenital Pulmonary Airway Malformations: Thoracoamniotic Shunting Versus Expectant Management

OBJECTIVE: Describe prenatal imaging characteristics, perinatal and postnatal outcomes in fetuses with isolated macrocystic congenital pulmonary airway malformations (CPAM) undergoing thoracoamniotic shunting (TAS) and expectant management. METHODS: Retrospective cohort study of 123 fetuses with isolated macrocystic CPAM managed at the Ontario Fetal Center (1998-2024). Prenatal ultrasound features, perinatal outcomes, and postnatal surgical data were described for fetuses undergoing TAS and expectantly managed. Predictors of mortality were assessed in the TAS group. RESULTS: TAS was performed in 30/123 (24%) of cases. Shunted fetuses had higher CPAM volume ratio (CVR) (1.5 vs. 0.5), larger cyst diameter (3.4 vs. 1.0 cm), mediastinal shift (58% vs. 7%), and hydrops (16.7% vs. 0%). Lesion size decreased after TAS in 80% of cases; however, survival was lower (85% vs. 100), and preterm delivery was more frequent (24% vs. 7%). Among shunted cases, CVR > 2 or persistent hydrops were associated with perinatal mortality. Neonatal respiratory support was required more often following TAS (86% vs. 25%). Most infants underwent postnatal resection, occurring earlier after TAS (0.1 vs. 7.0 months). CONCLUSIONS: Macrocystic CPAM represents a high-risk subtype of congenital lung malformations, with a substantial proportion requiring fetal intervention, neonatal respiratory support, and postnatal surgical resection. These findings support tertiary surveillance and delivery.