Significance of an echogenic intracardiac focus in fetuses at high and low risk for aneuploidy.

Our objective was to evaluate the significance of an echogenic intracardiac focus in a mixed population of fetuses at high and low risk for aneuploidy. Over a 1 year period, we prospectively identified all fetuses with an echogenic intracardiac focus seen during prenatal sonography. A detailed structural evaluation was performed on each fetus as permitted by gestational age. The location and number of foci were tabulated prospectively, as were associated abnormalities. Follow-up was obtained by review of the medical record. Of the 290 fetuses who had an echogenic intracardiac focus, 14 of them were aneuploid (4.8%). Of the 290 mothers, 125 women were aged 35 years or older and 165 women were younger than 35 years old. Among the 125 fetuses born to women 35 years or older, eight were aneuploid fetuses (6.4%), while among the 165 fetuses of younger mothers, six were aneuploid fetuses (3.6%) (rate ratio = 1.8; 95% confidence interval [extremes] = 0.6, 4.9). Only one of the 14 aneuploid fetuses had an echogenic intracardiac focus as the only sonographic finding, and this occurred in a woman aged 41 years. The majority of the echogenic intracardiac foci (87.6%) were located in the left ventricle, while 4.8% of the foci were right-sided and 7.6% were bilateral. Among the 14 aneuploid fetuses, 14% had bilateral echogenic intracardiac foci and 7% had right-sided foci. Among the euploid fetuses, 7.3% had bilateral echogenic intracardiac foci and 4.7% had right-sided foci. In conclusion, we have shown that the presence of an echogenic intracardiac focus does raise the risk that the fetus has a chromosomal abnormality, most commonly Down syndrome, although all but one aneuploid fetus in our study had other sonographic findings.