Transposition of the Great Arteries in Fetal Life: Accuracy of Diagnosis and Short-Term Outcome.

Objective: To review our series of prenatally diagnosed transposition of the great arteries (TGA) to analyze the accuracy of fetal echocardiography for achieving a precise diagnosis of the TGA type (simple vs. complex) and to examine the short-term outcome.

Methods: A total of 94 cases of simple and complex TGA types (ventriculoarterial discordance with atrioventricular concordance) prenatally evaluated in our referral center between 1998 and 2014 were included. Fetuses with additional congenital anomalies and those with incomplete follow-up were excluded. Prenatal diagnostic accuracy and short-term survival were analyzed for the different types of TGA.

Results: The TGA type was correctly ascertained prenatally in 93.3%. Most fetuses were diagnosed with simple TGA (62.7%). There were 6 discrepancies: 5 fetuses with simple TGA had postnatally TGA + ventricular septal defect (VSD; n = 3) or TGA + VSD + coarctation of the aorta (n = 2), and 1 fetus with TGA + VSD postnatally showed severe left ventricular outflow tract obstruction. The mortality rate was 6.6%; it was higher in complex versus simple forms (12.8 vs. 1.9%, p = 0.038), and in cases with intramural coronary artery versus those without (60 vs. 3.5%, p < 0.001). We found no relationship between the arrangement of the great arteries and coronary arterial abnormalities.

Conclusions: Simple TGA has a better outcome than the complex forms. A discrepancy rate of 7% with potential influence on the prognosis of survival between the prenatal diagnosis of the TGA type and the definitive diagnosis was found.