Fetal heart scans

A fetal heart scan is similar to the routine scans that you have during pregnancy, but focuses specifically on your baby’s heart. 

At Great Ormond Street Hospital (GOSH) we use ultrasound to take pictures of the heart to see how it is developing and to look at the blood flow around it. In most cases, it is to check that the heart is developing normally. Many heart problems can be detected during pregnancy but a small number can only be detected after birth.

The Fetal Cardiology Serviceis part of the Cardiothoracic team at GOSH. We are a team of experienced doctors, nurses and sonographers (ultrasound radiographers) who specialise in the care of babies with heart conditions both before and after birth. Although we are based at GOSH, we hold clinics in specialist centres and other hospitals. We provide support and information to any family whose unborn baby may have a heart abnormality.

The aim of the Cardiothoracic team is to develop a close and supportive partnership with parents and their children to ensure a positive experience for patients, families/carers and ourselves. We recognise that the hospital environment can prove to be demanding, worrying and intense and we aim to alleviate some of the stress to families by talking openly, listening to each other and working together in the best interests of the child. This way we hope to create a partnership with families that is built on mutual respect and trust.

Your obstetrician (doctor specialising in pregnancy), family doctor (GP) or midwife may have suggested that you have this scan so that your baby’s heart can be checked in more detail. This does not necessarily mean that there is a problem with your baby’s heart. In most cases, the fetal scan is done after your routine 20-week scan. If we do detect a problem, we will explain this to you and discuss the options available.

Common reasons for a fetal heart scan include:

• Your routine scan does not show the heart clearly or shows that there may be an abnormality of your baby’s heart.
• Either parent or a previous child has a congenital heart abnormality.
• You have a condition such as diabetes or a connective tissue disorder.
• The routine 20-week scan may have shown an increased amount of fluid behind your baby’s neck – this is called increased nuchal translucency.
• There are other abnormalities suspected.
• You are on medication, for example, for epilepsy or depression.
• Your baby has an abnormal heart beat.
• You are expecting twins or triplets or more.

Some fetal heart scans can be carried out at 14 weeks. This may be because you have had a previous child with a heart problem or there is increased nuchal translucency.

However, if the fetal heart scan is carried out early, it will need to be repeated at around 20 weeks even if it is normal.

You do not need to prepare for the scan and you do not need a full bladder. The person carrying out the scan will explain to you exactly what is going to happen during the scan but it is very similar to your routine pregnancy scans. They will put some gel on your abdomen and use an ultrasound probe to get a clear set of pictures.

A number of factors can affect how good a view the sonographer or doctor can get of your baby’s heart. These include the age and position of your baby, the amount of amniotic fluid surrounding them as well as your body weight.

Usually, a fetal heart scan can take between five and 20 minutes depending on the factors outlined above.

No. Ultrasound scans use only sound waves, rather than x-rays or magnetism, to form pictures. The gel used on your abdomen may feel a bit cold but we will try to warm it up before we apply it.

While this may be a very anxious time for you, it is important that we get as much information as possible. When the scan is over, the results will be explained to you. For many people the results will show no abnormalities and no further heart scans will be needed. If your baby is found to have a heart problem, the fetal cardiologist and fetal nurse counsellor will explain the findings to you and discuss the options available.

See our information sheet on Fetal heart scans: what happens next