Congenitally corrected transposition of the great arteries (ccTGA) with biventricular physiology is presumed to carry a favorable outcome. We aimed to better characterize the impact of prenatal diagnosis on conduction disorders, interventions, and mortality. Secondary objective was to examine outcomes in isolated ccTGA.

An international, multicenter, retrospective cohort study was conducted in 29 tertiary hospitals (6 countries) from 1990–2018. Patients with a single ventricle, heterotaxy syndrome, or valvar atresia were excluded.

Of 331 ccTGA patients with a median follow-up of 8.6 years [IQR: 3.5–14.1], 128 (38.7%) were diagnosed prenatally at a median gestational age of 22 weeks. As compared to the postnatal group, prenatally diagnosed patients experienced earlier cardiac conduction disorders (median age at diagnosis of conduction disorders: 0.3 versus 2.7 years, P = 0.010), earlier pacemaker implantation (median age at pacing: 6.5 years [2.5–11.6] versus 0.9 year [0.1–3.0], P < 0.001) and earlier surgical intervention (intervention-free survival rate at 3 years: 50.3% versus 34.7%, P < 0.001). The 3-year survival rate was significantly lower in patients diagnosed prenatally (91.1% versus 98.4%, P = 0.002) and the median age at death was significantly younger among patients diagnosed prenatally (0.2 versus 7.0 years, P < 0.001). In both groups, isolated ccTGA ( n = 63, 19%) was associated with superior outcomes with no intervention in 46.8% and only one death.

Prenatally diagnosed patients with ccTGA had earlier conduction disorders and interventions than postnatally diagnosed patients and died at a younger age. Outcomes were best in patients with isolated ccTGA.