Heart disease in babies are commoner than thought; about 5 % of all pregnancies have a baby with heart defects and 1 % of all live births have heart defects. Foetal echocardiography (Foetal echo) is the detailed evaluation of the heart of the foetus (baby in the mother’s womb) to check for any abnormalities so that decisions can be taken during the pregnancy in the best interest of the foetus.
How is the test performed?
It is usually done during the second trimester of pregnancy when the woman is about 16 – 22 weeks pregnant. The procedure is similar to that of a pregnancy ultrasound; you will lie down for the procedure. The test can be performed on your belly (abdominal ultrasound) or through your vagina (transvaginal ultrasound).
In an abdominal ultrasound, the person performing the test places a clear, water-based gel on your belly and then moves a hand-held probe over the area. The probe sends out sound waves, which bounce off the baby’s heart and create a picture of the heart on a computer screen. In a transvaginal scan, a much smaller probe is placed into the vagina. A transvaginal ultrasound can be done early in the pregnancy and produces a much clearer image than an abdominal ultrasound.
Why is it done?
Foetal echocardiography is done under the following circumstances.
- A routine pregnancy ultrasound detected an abnormal heart rhythm or possible heart problem in the unborn baby.
- A sibling or other family member had a heart defect or heart disease
- The mother has type 1 diabetes, lupus, or any metabolic disease
- Mother has rubella (infection) during pregnancy
- Mother has used medicines that can damage the baby’s developing heart
- Mother used drugs or alcohol during pregnancy
- An amniocentesis revealed a chromosome disorder
What is the best gestation period to do a Foetal echo?
Between 18 and 20 weeks of pregnancy in routine cases. In special situations with additional risks (abnormal first-trimester scan, parent or sibling with heart defect etc.) it can be done between 14 and 16 weeks of pregnancy.
How does one prepare for the test?
No special preparation is needed for this test.
How does the Test feel?
You will not feel the ultrasound waves.
What it can show?
- Structures of the baby’s heart
- Blood flow through the heart
- Heart beating rhythm
When do I get the report?
Usually, the report will be ready by the same day/ next day. For certain conditions which need to be discussed in the team, the reporting may be delayed by 48 – 72 hours.
What does a normal result mean?
The echocardiogram found no problem in the Foetal heart relevant to the gestational period.
What does an abnormal result mean?
Abnormal results may be due to:
- A problem in the way baby’s heart has formed (congenital heart disease)
- A problem with the way the baby’s heart works
- Heart rhythm disturbances (arrhythmias)
What are the risks of getting a Foetal Echocardiography?
There are no known risks to the mother or foetus.
What defects cannot be detected?
Some heart defects cannot be seen before birth even with foetal echocardiography. These include small holes in the heart of mild wave problems. Sometimes, it may not be possible to see every part of the blood vessels leading out of the baby’s heart. Certain diseases may evolve during pregnancy (eg: heart muscle disease, valve narrowing/ leak) and may not be seen at the scanning time.
- The test may need to be repeated at times
- Certain abnormal findings may be a variant from the routine and not a defect as such but may need serial assessment in foetal life (and sometimes after birth) to make sure it does not evolve into a disease
- If the health care provider finds a problem in the structure of the heart, a detailed ultrasound may be done to look for other problems with the developing baby.