Diagnosis, characterization and outcome of congenitally corrected transposition of the great arteries in the fetus: a multicenter series of 30 cases

OBJECTIVE: To describe the anatomy, associated anomalies and outcome of 30 cases of congenitally corrected transposition of the great arteries (ccTGA) detected prenatally. METHODS: This was a retrospective observational study of the 30 cases of ccTGA confirmed at autopsy or postnatal echocardiography seen at one of three referral centers from 1994 to 2003. The following data were considered: gestational age at diagnosis, cardiac anatomy, associated cardiac and extracardiac anomalies and fetoneonatal outcome. All fetuses underwent fetal echocardiography and a detailed anomaly scan, with follow-up scans at 3-4-week intervals until delivery. The diagnosis was confirmed at autopsy or after delivery. Follow-up data were retrieved from the clinical files of the patients. RESULTS: The mean gestational age at diagnosis was 25.5 weeks. Intracardiac defects associated with the ccTGA included a ventricular septal defect in 21 cases, pulmonary outflow obstruction in 12 cases, an abnormal tricuspid valve in 10 cases, ventricular hypoplasia in five cases and dextro/mesocardia in five cases. The karyotype was normal in all 24 newborns, and unknown in the cases which resulted in termination of pregnancy (n = 5) or intrauterine death (n = 1). There were associated extracardiac anomalies in four cases only. Three of the four cases of atrioventricular block (AV block) developed in the third trimester, while the fourth appeared after birth. There were nine deaths (five terminations, two perinatal deaths and two infant deaths). The remaining 21 (70%) newborns were alive at a median follow-up time of 32 months, 11 of them after various surgical procedures. CONCLUSIONS: Our data suggest that in fetuses with ccTGA the risk of chromosomal and extracardiac anomalies is low, in accordance with postnatal data. The spectrum of associated cardiac lesions is consistent with that reported in the pediatric literature. These data may be of use during prenatal counseling since no figures regarding survival and/or outcome of ccTGA in the fetus have been reported so far.