Objective: To assess the diagnostic accuracy of fetal echocardiography and the outcome of cardiac malformations diagnosed in utero.
Design: A retrospective study.
Methods: The archives of our ultrasound laboratory were searched for fetal cardiac abnormalities in the period 1991-2001.
Results: Diagnosis of a fetal cardiac anomaly was made in 339 pregnancies at a mean gestational age of 26.2 weeks. Pathology or a detailed postnatal follow-up was available in 260 cases, and the prenatal diagnosis was accurate in 236 cases (91%). Discrepancies included nine false positive diagnoses (six ventricular septal defects and three coarctation of the aorta) and 15 cases in which a cardiac anomaly different from the one suspected in utero was documented. Of the 142 fetuses with isolated cardiac malformations (no extracardiac anomalies, normal chromosomes) that were delivered in our center, 114 were alive (80.2%) at a mean follow-up of 38 months (range, 1-120 months). In this group of patients, conotruncal anomalies and univentricular lesions were the most frequent types of anomaly, and had a survival rate of 87% and 57%, respectively. Hypoplastic left heart was the most frequent isolated congenital heart defect in infants that were delivered (19 cases) and it was associated with a survival rate of 37%.
Conclusion: In expert hands, fetal echocardiography is highly accurate. The long-term prognosis of cardiac lesions diagnosed in utero is similar to that reported in series of infants diagnosed after birth. The only exception is hypoplastic left heart in which the survival rate is much lower than expected from postnatal studies.