FETAL ECHOCARDIOGRAPHY: THE PURPOSE, PROCEDURE & RISKS

Dr. Zohra Ahmad
Fetal Medicine Specialist
Institute of Human Reproduction

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Incidence of Congenital heart disease in India is 1/100 live births. Many of these remain undiagnosed in pregnancy and become evident only at birth or neonatal period/infancy. Of these, approximately 20% may require urgent treatment. It is possible to diagnose congenital heart disease in fetal life itself using fetal echocardiography in expert hands.

What is Fetal Echocardiography?

It is a test similar to ultrasound. It allows the doctor to see the structure and function of the baby’s heart in detail. It also enables the doctor to see blood flow through the fetal heart and cardiac rhythm. The scan is done by a radiologist or a fetal medicine specialist.

Fetal Echocardiography Timing: When should you do it?

Fetal echocardiography is ideally done after 20 weeks period of gestation. Although it can be done till the third trimester, the ideal time is 20-24 weeks. In later pregnancy, fetal position and shadowing by fetal spine/limbs may prevent us from getting optimal cardiac images.

Procedure & General Instructions for Fetal Echocardiography

It is done similar to other pregnancy scans. There is generally no need of drinking water or filling up of the urinary bladder. The scan usually takes approximately 30 minutes -2 hours depending on the position of the baby. If the baby’s position is unfavourable for the scan, we may have to rescan after some time. The scan is generally done transabdominally.

Who should go for Fetal Echocardiography?

● First-trimester scan showing abnormalities like increased nuchal translucency, tricuspid regurgitation or ductus venosus a-wave reversal

● As a second opinion if previous tests are inconclusive or any suspicion of cardiac abnormality in a routine pregnancy scan
● Family history of heart disease
● Previous child with heart disease
● Twin pregnancy
● Diabetes Mellitus / Gestational Diabetes
● Autoimmune disorders like SLE
● History of drugs like antiepileptics or antipsychotics by mother

Why do you need to go for Fetal Echocardiography? Why is Fetal Echocardiography Important?

● Detecting some surgically correctable heart diseases in the fetal period helps us guide the couple for delivery in proper tertiary care set up with pediatric ICU care.
● Some complex congenital heart diseases like hypoplastic left heart syndrome may have a poor outcome with palliative treatment only available. In such cases, informed choice of termination can be given to the parents.
● Some congenital heart diseases may also be associated with chromosomal malformations / genetic disorders, in such cases, we can offer invasive testing in the interest of guiding the couple for future pregnancies.
● Certain rhythm abnormalities can be the first pointer for autoimmune diseases like systemic lupus erythematosus.

Are there any risks associated with Fetal Echocardiography?

There are no known risks with fetal echocardiography as it is done with ultrasound which does not involve radiation.

Limitations of Fetal Echocardiography

The doctor can’t use echocardiography to diagnose all conditions. Some conditions like holes in the heart- atrial or ventricular septal defect are difficult to see even with the best equipment.

There may be evolving defects which appear later in gestation such as pulmonary stenosis, and hence are not amenable to diagnosis before 24 weeks.