Introduction
Echogenic focus is a finding seen in the ultrasound examinations, done in the second trimester of pregnancy. It is considered a common finding and will not cause harm to the development of the baby. In rare cases, it can cause genetic mutations and antenatal tests are done to find any chromosomal abnormalities.
What Is Echogenic Cardiac Focus?
During prenatal ultrasound examinations, a small bright spot is often observed in the region of the fetal heart. This common finding, an echogenic focus, does not adversely affect the developing heart's functionality. Echogenic foci are typically seen in the left ventricle during the second and third trimesters. They are caused by small deposits of calcium, which is a natural mineral present in the body. In ultrasound scans, areas with more calcium appear to look brighter.
They are common and seen in about one out of five babies. Some ultrasound scans may show more than one echogenic focus distributed in the infant's heart. These are not attached to the chamber walls of the heart, found in the ventricles within the papillary muscles or chordae tendineae. It represents the mineralization within the papillary muscles. The echogenic intracardiac focus should have the same echogenicity as the fetal bone and move along with heart motion. Higher incidence among Asians, and seen in 4 % of all pregnancies.
What Are the Radiographic Features of Echogenic Focus?
Echogenic cardiac focus is found in routine prenatal ultrasound examinations, done around 18 to 20 weeks. Echogenic focus found in the absence of other ultrasound findings, is called isolated echogenic intracardiac focus.
The radiographic features are:
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Seen as a small bright echogenic focus, bright as a bone.
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Seen within the fetal heart.
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Tissue harmonic imaging is turned off during evaluation, as it may result in false positive outcomes.
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They are seen as single-focus and less than 3 mm.
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Should be differentiated from normal papillary muscle.
Why Is Echogenic Focus a Cause of Concern?
In the majority of cases, infants with intracardiac focus will be born healthy. And rarely in some cases, it may result in chromosomal change. Echogenic foci are related to cardiac malformation or congenital heart defects.
The presence of echogenic focus can be related to the chromosomal abnormality called Down syndrome. It affects chromosome 21, resulting in developmental defects in the newborn.
What Are the Prenatal Tests to Screen for Genetic Abnormalities?
Routine tests like integrated screening and cell-free DNA screening (also called non-invasive prenatal testing or NIPT) are carried out, including blood tests, done to find out the chances of chromosomal abnormalities like Down syndrome, Edward's syndrome, or Patau's syndrome.
In cases with echogenic cardiac focus, suspecting a chromosomal mutation, amniocentesis is requested. In amniocentesis, the amniotic fluid present in the sac is collected with the help of a long needle inserted along the abdominal wall guided by ultrasound. A small sample of amniotic fluid is sent for testing. The results are highly accurate in predicting possible birth defects.
A detailed ultrasound is done to look for chromosomal mutations and followed by amniocentesis is done. If the cells of amniotic fluid show a genetic mutation, a genetic counselor will inform about all the possible outcomes for the child. The parents are informed and they prepare for the baby. If not, the decision is left to the parents alone. If there is no suspected genetic mutation or no detected abnormalities in amniocentesis there is no cause of concern. The doctors will continuously monitor the fetus through ultrasound scanning. The echogenic focus is recorded and studied.
Also after birth, the child is carefully observed for any conditions or genetic defects. The cardiac functions are also monitored. As the child is not showing any symptoms till the age of two years, the health of the baby is fine and everything seems perfect. Nothing stops the child from growing up healthy.
What Is the Treatment and Prognosis?
Clinically there is no treatment for echogenic intracardiac focus. The interpretation of the cardiac echogenic focus is based on maternal risk factors and other sonographic changes. When echogenic foci are accidentally found alone during a routine ultrasound of a healthy pregnancy, they are considered harmless and not a cause for concern. Some experts even suggest that genetic testing (karyotyping) is unnecessary during the middle stage of pregnancy in such cases.
In simple terms, if these bright spots are seen by chance in an otherwise normal pregnancy, they are not seen as a problem, and there is no need to perform additional genetic testing during the second trimester of pregnancy.
High-risk pregnancies show chances of aneuploidy like Down syndrome and trisomy 21 and are said to be a soft marker. Multiple or bilateral echogenic foci increase the risk associated with it.
The echogenic focus usually disappears during the third trimester.
Conclusion
Although discovering something unusual during a prenatal ultrasound can be alarming, echogenic intracardiac focus is generally a benign finding in otherwise healthy pregnancies. Close monitoring and, if necessary, additional tests like amniocentesis can help identify any potential chromosomal abnormalities. Most of the time, there is no need for undue concern, and parents can prepare for the arrival of their baby with confidence.
