Fetal echocardiography: a detailed scan of your baby's heart

Medically written by Dr. Sushma Dhakal, MBBS · MD (Obstetrics & Gynaecology) · Fellowship in Fetal Medicine · Updated 30 October 2026 · 3 min read

Fetal echocardiography, or a fetal echo, is a detailed ultrasound of the baby's heart during pregnancy. The routine anomaly scan already checks the heart, but a fetal echo looks more closely at its structure, the major blood vessels, the heart rhythm and blood flow.

Congenital heart disease is the most common major birth difference, affecting roughly 8 in every 1,000 babies. Many cases occur in families with no risk factors, which is why the heart is examined in every anomaly scan.

Who is offered a fetal echo?

A possible heart concern seen on the anomaly scan or another scan.
An increased nuchal translucency (usually 3.5 mm or more) at the NT scan, even when chromosomes are normal.
A parent or previous child with congenital heart disease.
Pre-existing diabetes in the mother, or certain medicines taken in early pregnancy (for example some anti-epileptic drugs).
Monochorionic twins, pregnancies after IVF in some cases, or a known genetic condition in the baby.
An abnormal fetal heart rate or rhythm.

When is it done?

A fetal echo is usually done at 18–24 weeks, when the heart is large enough to see in detail. In high-risk pregnancies an early heart assessment can be done at 13–16 weeks, followed by a repeat scan later. The scan takes 30–60 minutes and is done through the abdomen. It is safe and painless.

What does it check?

The four chambers of the heart and the walls between them.
The valves and how they open and close.
The two main arteries (aorta and pulmonary artery), how they leave the heart and cross each other.
Blood flow using colour Doppler, and the heart rate and rhythm.

Limitations

A fetal echo detects most major heart conditions, but no scan can find everything. Small holes between the chambers, some valve problems, and narrowing of the aorta (coarctation) can be difficult to see before birth. Some normal fetal connections, such as the ductus arteriosus and foramen ovale, close only after birth, so related conditions cannot be diagnosed in pregnancy. Image quality can also be limited by the baby's position or the mother's body build.

If a heart problem is found

You will have time to discuss what the finding means, usually together with a paediatric cardiologist. This may include further tests, such as genetic testing by amniocentesis, because some heart conditions are linked with chromosomal changes. Knowing before birth helps plan delivery at a hospital with the right neonatal and cardiac team, which can make an important difference for the baby.

Have questions about your pregnancy?

Book a consultation with Dr. Sushma Dhakal, Fellowship-trained fetal medicine specialist (FMF UK certified).

Book this scan Request Counselling

Frequently asked questions

When is the best time for a fetal echo?

Usually between 18 and 24 weeks. An early heart scan at 13–16 weeks may be added in higher-risk pregnancies.

Is a fetal echo different from the anomaly scan?

Yes. The anomaly scan checks the heart as part of the whole baby. A fetal echo is a longer, focused heart examination.

Can a fetal echo miss heart problems?

It finds most major conditions, but small holes, mild valve problems and some narrowings can be hard to see before birth.

Is the scan safe?

Yes. It is an ordinary ultrasound through the abdomen and is safe for you and your baby.

This guide is for general information only and is not a substitute for personal medical advice. Every pregnancy is different. Please consult your doctor about your own situation. In an emergency, go to the nearest hospital.