Multiple fetal intracardiac echogenic foci: not always a benign sonographic finding

Isolated left-sided echogenic foci in the fetal heart are considered as a benign condition, probably representing a normal variant of the development of papillary muscles. The objective of the present study was to evaluate the incidence and significance of multiple or diffuse echogenic foci in the fetal heart. We analysed retrospectively 25 725 ultrasound examinations conducted for fetal malformations between 12 and 24 weeks' gestation. In the study group, echogenic intracardiac foci were observed in 44 cases (0.17 per cent). In 35 fetuses, these foci were confined to the region of the papillary muscles/chordae tendinae as an isolated finding in the left side of the heart. All these fetuses had an uneventful neonatal follow-up. However, in nine of these cases, diffuse echogenic foci were demonstrated in various regions of the fetal heart, five of them with involvement of the right ventricle. In five of the nine cases, other major pathologies were found. In one case, a missed abortion occurred and in one case of early termination of pregnancy, calcifications were demonstrated in the endocardium on histological examination. Only in two of the nine fetuses was the outcome uneventful. Our findings suggest that diffuse echogenicity in the fetal heart, especially when the right ventricle is also involved, may signal a poor prognosis and deserves a further search for associated pathologies. This is in contrast to the benign character of an isolated left-sided echogenic focus.