What determines survival in transposition of the great arteries? Insights from a 10-year cohort of prenatally diagnosed cases.

Objective

To evaluate prenatal and postnatal outcomes of fetuses with transposition of the great arteries (TGA) and to identify prognostic factors affecting neonatal survival.

Methods

This retrospective study included fetuses prenatally diagnosed with TGA between January 2015 and December 2024 at a tertiary referral center. Diagnosis was based on fetal echocardiography demonstrating normal atrioventricular connections with ventriculo-arterial discordance and a parallel course of the great arteries. Perinatal management included planned delivery at a tertiary center, prostaglandin E1 infusion, and arterial switch operation (ASO). Postnatal data included balloon atrial septostomy (BAS), coronary artery anomalies, extracorporeal membrane oxygenation (ECMO), and survival.

Results

A total of 116 neonates with postnatally confirmed d-TGA were analyzed. Of these, 63 (54.3%) were male and 53 (45.7%) female. BAS was performed in 23/116 (19.8%), not performed in 66/116 (56.9%), and data were not available in 27/116 (23.3%) cases. BAS was required in neonates with restrictive interatrial communication, indicating inadequate intercirculatory mixing. Coronary artery anomalies were identified in 8/116 (6.9%) cases and were significantly more frequent among non-survivors (30.8% vs 4.9%; OR 11.0, 95% CI 2.35-51.56; p = 0.005). Postnatal mortality occurred in 13/116 (11.2%), mainly related to coronary anomalies and severe hemodynamic instability. The overall postnatal survival rate was 88.8% (103/116).

Conclusion

Prenatal diagnosis of d-TGA enables delivery in tertiary centers with immediate prostaglandin support and timely intervention. Early outcome is primarily determined by effective intercirculatory mixing and coronary artery anatomy.