Cardiac Scan (Fetal Echocardiography)

Why is it important to examine the baby’s heart during every scan?

Heart defects (cardiac anomalies or congenital heart disease) are the most common human anomalies.
In fact, cardiac anomalies are much more common than trisomy 21 (Down’s Syndrome) and can
sometimes be life-threatening to the baby.

The vast majority of heart defects affect babies that have healthy parents with no family history of cardiac
problems; however, in some cases, maternal diabetes or increased nuchal translucency (NT) can suggest
and increased risk of cardiac anomaly.

Key facts about the baby’s heart:

- Composed of four chambers, four valves, a foramen ovale, two arteries, and six veins
- Relatively small, occupying about a third of the baby’s chest
- The heart rate is about 2.5 contractions per second

The complexity of the baby’s heart in combination with the above-mentioned descriptions, makes
imaging very challenging. Furthermore, heart defects are highly variable, with over 100 heart anomalies
identified to date. This highlights why many heart defects (even life-threatening ones) often remain
undiagnosed until birth.

We do a thorough scan of the heart during any of our scans performed from 12-36
weeks.

Not only are we experts in performing fetal echocardiography or fetal echo (examination of your baby’s
heart), we also have a long-standing record of training other professionals in the technique.

We have developed a three-stage protocol for congenital heart disease screening:

Early Baby Scan at 12-13 weeks: By this stage of pregnancy we are able to exclude some severe heart
defects, such as transposition of the great arteries and hypoplastic left heart syndrome, as well as provide
reassurance for the parents.

Anomaly Scan at 21-23 weeks: By this stage we are able to exclude some major anomalies which would
have been undetectable at 12-13 weeks. We will also try to exclude some moderate and minor cardiac
defects such as ventricular septal defects (“hole in the heart”).

Baby Development Scan at 28-34 weeks: During this scan we aim to exclude heart anomalies, which
manifest later in the pregnancy. These conditions are rare; however, some of them can be very serious or
even life-threatening. These include heart rhythm abnormalities, heart tumours, heart valve abnormalities,
and some ventricular septal defects may only be detectable at this stage.

Unfortunately, it is impossible to exclude all heart defects in 100% of pregnancies because some
anomalies may manifest only after birth. These include coarctation of the aorta, patent ductus arteriosus,
among others. In other rare circumstances, detectable cardiac anomalies go undiagnosed due to
technical reasons during imaging.