If you are referring to an 'echogenic intracardiac focus', seen in a fetus during a sonogram
- then it is essentially a bright white spot, seen within a chamber of the baby's heart
, having the same brightness as bone.
It is considered a 'soft' marker for down's syndrome.It is present in 15-30% of fetuses that have down's syndrome, and ~5% of normal fetuses. Additional testing (amnio, harmony, mat21.