Objective: To determine whether the presence of an isolated fetal cardiac echogenic focus should be an indication for fetal echocardiography.
Methods: We reviewed our fetal echocardiography and obstetrics databases from January 1992 through July 1999. The study groups were formulated from patients referred for fetal echocardiography. Patients referred for echocardiography because of a single isolated fetal cardiac echogenic focus were compared with patients referred for other indications. The sensitivity, specificity, and positive and negative predictive values were calculated for an isolated echogenic focus as a marker for structural cardiac abnormalities as detected by fetal echocardiography.
Results: Of 10,406 fetuses seen for ultrasonography, 1908 had fetal echocardiography. Cardiac abnormalities were identified in 3.4% (65 of 1908) of the fetuses that had echocardiography. The prevalence of an isolated echogenic focus was 2.2% (230 of 10,406) and was the indication in 12.1% (230 of 1908) of our echocardiograms. Only 1 of the 230 fetuses with an isolated echogenic focus had a structural cardiac defect (membranous ventricular septal defect). An isolated echogenic focus as a marker for congenital cardiac defects resulted in sensitivity and specificity of 1.5% and 87.6%, respectively. The positive and negative predictive values were 0.4% and 96.2%, respectively The relative risk for an echogenic focus in predicting congenital cardiac defects was 0.11 (95% confidence interval, 0.02-0.82).
Conclusions: An isolated fetal cardiac echogenic focus is not an efficacious marker for congenital cardiac defects. It should not be the sole indication for fetal echocardiography.