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

Abstract

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.

Sonographic markers of fetal trisomies: second trimester.

“…[122][123][124][125] Bettelheim et al 122 found EIF located in the left ventricle in 96% of cases, in combined left and right ventricles in 4.3%, and isolated to the right ventricle in just 0.7% (1 of 150). Bromley et al 116 concluded that right-sided and bilateral EIF combined together had an approximately 2-fold greater risk of aneuploidy compared with leftsided foci, and others have also found that echogenic foci involving both ventricles are more associated with aneuploidy. Wax and Philput 123 reported that aneuploidy was more common when echogenic foci involved both ventricles compared with either ventricle alone.…”

Genetic Screening for Aneuploidy in the Second-trimester

“…In a study of 9263 low-risk pregnancies, 153 fetuses had EIF and none of them had trisomy 21. 19 Bromley et al 20 have shown that the risk of aneuploidy is also increased when EIF is found in fetuses of low-risk pregnant women. Nevertheless, on the basis of current literature there is a strong evidence to support the fact that EIF is more prevalent in fetuses with chromosomal defects specifically trisomy 13 and trisomy 21.…”

Prenatal Diagnosis of Down Syndrome

“…It is observed in 3-4% of normal fetuses and disappears spontaneously in the third trimester. 39 If the size of echogenic intracardiac focus is large or there are multiple of them, the risk of aneuploidy increases. Bromley et al 40 reported that the risk of aneuploidy is 2 times higher when echogenic intracardiac focuses are in the right ventricle or bilateral than when they are only in the left ventricle.…”