What is Congenital Heart Disease?

Congenital heart disease (CHD) is the term used to describe a number of different problems that affect how well the heart works. You can read more about how the heart works here. 

Below is our animation that shows how a baby’s heart develops during pregnancy.

The word “congenital” means the problem occurs while the fetus is being formed, meaning the condition is present at birth.

There are a large number of different defects, some are mild and don’t need treatment, while some are life-threatening and need open heart surgery or other medical interventions. Sometimes the term congenital heart “disease” is used instead of “defects” – either way, the name is commonly shortened to CHD.

CHD is the most common congenital birth defect – affecting around 1 in every 125 babies – and around 3,000 surgeries or catheter procedures take place on babies under one year of age every year.

CHD is responsible for 47% of all deaths from congenital anomalies, and accounts for up to 12% of all infant deaths – that’s more than 1 in 10.

However, thanks to advances in detection and treatment – and the massive leaps made in paediatric heart surgery in recent decades – outcomes are improving and 80% of babies born with CHD will now survive into adulthood.

Causes of CHD

For most babies, there is no obvious cause of their heart condition. However, there are some things that are known to increase the chances of having CHD, including a family history of CHD; the baby also having a chromosome defect (such as Down’s Syndrome); or the mother having certain infections during pregnancy or poorly controlled type one or two diabetes.

Detection of CHD

Experts estimate that around 75% of major heart problems could be detected during pregnancy – most commonly during the standard 20 week ultrasound scan. However, at the moment, less than half of defects are – in some regions the detection is as low as around 20%.

Around a third of defects are spotting during standard newborn checks in hospital, with the remaining cases (approximately 1,000 newborns each year) sent home with no diagnosis. These babies are most likely to be diagnosed only when they begin to fall ill or show the early signs of heart failure.

You can read more about detection during pregnancy in our ‘Are you Pregnant’ page and more about the signs a baby may have an undetected condition in the ‘Just had a baby?’ page.

Treatment of CHD

Mild heart problems often don’t need any treatment – for example, some holes in the heart close on their own.

If the condition is severe, then open heart surgery or a catheter intervention are the most likely treatments. Some of the most complex heart conditions require a series of surgeries spread over a number of years.

Many people with CHD will need treatment and/or regular checks throughout their life, and some will be on medication such as the blood thinner Warfarin.

While children’s heart surgery is very complex, and an incredibly distressing experience for the families concerned, it is worth remembering that the UK is one of the world leaders in this field. Survival rates are extremely high, and 80% of children with serious heart conditions now survive into adulthood.

Surgical centres in the UK

Heart surgery on babies and children is a very specialist field of medicine, so only 11 hospitals around the UK perform this surgery. They are:

As paediatric cardiac surgery provision has been removed from Belfast, some cardiac catheterisation and surgical emergencies are taking place in Our Lady’s Children’s Hospital, Crumlin in Dublin (OLCHC).

All other paediatric cardiac surgeries for patients from NI are currently being split between Evelina Children’s Hospital in London and Birmingham Children’s Hospital.

For other useful resources, please click here.


“The doctors kept saying, ‘You do know she’ll have to have open heart surgery, don’t you?’ and I did.”

You can follow the journey of heart mum Grace and her daughter Honey – from detection, to surgery, and then to life living with CHD – in these blog posts.