"Heart defect" is one of the most frightening phrases a parent can hear. It pulls in pictures of intensive care, tiny chests sutured shut, machines doing the work of a heart. Some children with CHD do go through that. Many never need anything more than monitoring. The umbrella covers a huge range, and the trajectory varies enormously depending on the specific defect.
If you have just had a CHD diagnosis — antenatal, at the newborn check, or after a child became unwell — the most important thing is the specific defect, not the general category. This guide gives the broad map; your cardiology team will give you the route.
Healthbooq covers complex conditions and the families who navigate them. For broader background, see our complete guide to child health.
How Common It Is
CHD affects approximately 1 in 100 babies in the UK — around 13 babies a day, close to 5,000 a year, according to the British Heart Foundation. That makes it the most common birth defect, more frequent than Down syndrome, cleft lip and palate, or any single neural tube defect.
Worldwide, the prevalence is similar. The number is roughly stable; it has not risen, though detection has improved.
About half of all CHD is mild — no surgery needed, normal life. About a third needs a single intervention or surgery in childhood. The remaining minority — perhaps 15–20 per cent — has complex CHD requiring multiple operations or staged management.
The Common Defects, Briefly
There are around 40 distinct conditions under the CHD umbrella. The most common ones:
Ventricular septal defect (VSD) — a hole in the muscular wall between the two lower chambers. About 30% of all CHD. Small VSDs often close on their own in infancy or childhood. Larger ones may need surgical or device closure.
Atrial septal defect (ASD) — hole in the wall between the upper chambers. Often missed in infancy because it produces few symptoms; sometimes only diagnosed in adulthood. Most are now closed with a device delivered through a leg vein, no open-heart surgery.
Patent ductus arteriosus (PDA) — a fetal blood vessel that should close shortly after birth fails to do so. Common in premature babies; often closes with medication or a device closure.
Pulmonary stenosis — narrowing of the valve between the right ventricle and the pulmonary artery. Mild forms need monitoring; significant narrowing is treated with a balloon dilation through a catheter.
Coarctation of the aorta — narrowing of the main artery leaving the heart. Repaired surgically, often in infancy.
Aortic stenosis — narrowing of the aortic valve. Treatment depends on severity and may include valve repair, replacement, or balloon dilation.
Tetralogy of Fallot — the most common cyanotic (blue) CHD. Four features: a VSD, an over-riding aorta, pulmonary stenosis, and right ventricular thickening. Repaired surgically in the first year, with most children doing well long-term.
Transposition of the great arteries — the two great vessels are swapped: the aorta comes off the right ventricle and the pulmonary artery off the left. Without intervention, this is fatal in infancy. The arterial switch operation, done in the first weeks of life, has transformed outcomes.
Hypoplastic left heart syndrome (HLHS) — the left side of the heart is severely under-developed. Until the 1980s this was almost always fatal. The Norwood procedure, introduced by William Norwood, opened up a survival path. Modern management is a staged three-operation approach (Norwood, Glenn, Fontan) over the first 4 years, with most children now surviving childhood.
How CHD Is Detected
Antenatal anomaly scan at 20 weeks. Examines the fetal heart in a structured protocol. Most complex defects (HLHS, transposition, large VSDs, severe valve problems) are picked up here. Tetralogy of Fallot is detected antenatally in about 50–60% of cases. Antenatal detection allows planned delivery at a specialist centre and rapid stabilisation.
Newborn examination at 6 hours and at the 6–8 week check. A doctor or trained midwife listens for murmurs and feels the femoral pulses, checks oxygen saturation. Many defects produce a murmur audible here.
Pulse oximetry screening. A simple finger or foot oxygen saturation reading on the day after birth, picking up cyanotic CHD that wouldn't yet show clinically. Now offered routinely in most UK maternity units.
Later presentation. Some defects — especially small ASDs and mild valve abnormalities — only show up on a routine listen at a school check, when an unrelated chest X-ray is taken, or in adulthood. Others present when a child becomes unwell with poor feeding, blue spells, breathlessness on feeds, or poor weight gain.
If you suspect something is wrong with your baby's heart — they breathe fast at rest, get breathless feeding, look blue around the mouth, sweat with feeds, or fail to gain weight — see the GP or out-of-hours service. Cyanosis (blue colour) at rest is a red flag and warrants A&E.
Treatment
What you need depends entirely on the specific defect.
Watch and wait. Many small VSDs and small ASDs are simply followed in clinic with regular echocardiograms. Many close spontaneously.
Catheter-based interventions — done through a vein in the leg under general anaesthetic, no open chest. Suitable for many ASD closures, PDA closures, balloon valvuloplasty for pulmonary stenosis, balloon dilatation for coarctation.
Open-heart surgery on cardiopulmonary bypass — needed for complex repairs: VSD closure, complete repair of tetralogy of Fallot, the arterial switch, the staged HLHS surgeries, valve replacement.
Heart transplantation — for the small minority of children whose hearts cannot be repaired or whose function deteriorates despite surgery.
UK paediatric cardiac surgery is concentrated in nine specialist centres following the 2013 Safe and Sustainable review: Great Ormond Street, Royal Brompton, Evelina London, Birmingham Children's, Bristol, Leeds, Liverpool Alder Hey, Newcastle Freeman, and the Royal Hospital for Children in Glasgow. Outcomes data is published openly by NICOR. Across all procedures, 30-day mortality is around 2–3%, varying significantly by complexity — simple VSD closures have very low mortality; complex Norwood procedures still carry around 10% perioperative risk in the UK.
Long-Term Outlook
Outcomes have transformed over the past 50 years. In the 1960s, the majority of children born with significant CHD did not reach adulthood. Today, the vast majority do, including those with the most complex conditions. As a result, the population of adults living with congenital heart disease (ACHD) now exceeds the population of children with CHD, requiring the development of specialist adult CHD services.
Long-term issues that may need ongoing attention:
- Recurrent or persistent residual heart problems requiring further intervention.
- Arrhythmias (irregular heart rhythms) — often years after surgical repair.
- Reduced exercise capacity in some.
- Pregnancy planning and management for women with CHD — preconception counselling is important.
- Endocarditis prevention with dental procedures in some forms of CHD.
Specialist follow-up at an adult congenital heart service continues for life in most patients with significant CHD.
Neurodevelopment
Children with complex CHD — particularly those who have had cardiopulmonary bypass surgery in infancy — have higher rates of:
- Learning difficulties
- Attention difficulties (ADHD-like patterns)
- Slower processing speed and working memory difficulties
- Social communication differences
- Motor coordination problems
This is documented across many cohorts; Jane Newburger's group at Boston Children's Hospital and the Heart and Brain consortium have laid out the picture clearly. The causes are multi-factorial:
- Brain development in utero is affected by the abnormal fetal circulation in many forms of CHD — abnormalities are visible on fetal MRI before any surgery happens.
- Bypass surgery itself, particularly with deep hypothermic circulatory arrest, carries some neurological risk.
- Prolonged hospitalisation in early infancy disrupts normal sensory and developmental experience.
UK specialist centres now include neurodevelopmental follow-up for children at higher risk — typically school readiness assessments, occupational therapy where needed, educational psychology referrals, and SENCo support in school. If your child has had complex CHD surgery and you're noticing learning, attention, or social differences, ask the cardiology team about developmental assessment.
Psychological Impact on the Family
A CHD diagnosis is one of the most distressing things parents can face. Even after successful treatment, anxiety and post-traumatic stress symptoms in parents are well-documented and often persist for years. Children with CHD also have higher rates of anxiety, depression, and school avoidance than the general population — driven by the experience of medical procedures, the awareness of being different, and sometimes by genuine activity limitations.
Specialist centres increasingly recognise this as part of medical care, not separate from it. Most have access to clinical psychology and family support services. Don't wait until things are bad — psychological support is just as legitimate a referral as any other from the cardiology team.
Practical Things to Know
Vaccinations. Children with CHD should have all routine vaccinations on schedule. They are also offered additional vaccines: annual flu vaccination from 6 months, RSV (palivizumab/nirsevimab in some defined high-risk groups during the first RSV season), and the routine pneumococcal schedule. Talk to the cardiology team and GP about specifics.
Infections. Children with significant CHD can become unwell faster than other children. Have a low threshold for medical advice with respiratory illnesses, particularly in infancy.
Endocarditis. Some structural defects raise the risk of bacterial infection of the heart valves. The cardiology team will tell you if your child needs antibiotic cover for dental procedures (current UK guidance is selective, not universal).
School and PE. Most children with CHD can take part in PE; specific restrictions vary by defect. Get a clear letter from the cardiology team for the school. Avoid blanket exclusion — most children benefit physically and socially from sport.
Air travel. Generally safe for most children with CHD. Specific advice for severe cyanotic defects or after recent surgery — ask the team.
Breastfeeding and feeding. Babies with significant CHD can struggle with feeds — they tire easily and burn calories rapidly. Frequent small feeds, fortified formula or fortified expressed breast milk under specialist dietitian guidance, and nasogastric supplementation are all part of the toolkit. Don't blame yourself if breastfeeding alone isn't sustaining weight gain — these are some of the hardest babies to feed and most need extra support.
UK Support Organisations
British Heart Foundation (bhf.org.uk) — research charity with information for families.
Children's Heart Federation (chfed.org.uk) — UK umbrella for children's heart charities; helpline and family support.
Little Hearts Matter (lhm.org.uk) — specifically for children with single ventricle conditions like HLHS.
Tiny Tickers (tinytickers.org) — supports families through diagnosis and ongoing care; campaigns for better antenatal detection.
Echo (formerly Right Heart Foundation) — peer support and family information.
Most specialist centres have local family support groups. Ask at your first cardiology appointment.
Key Takeaways
Congenital heart disease (CHD) is the most common birth defect — about 1 in 100 UK babies, around 5,000 a year. The umbrella covers around 40 different conditions, from a small hole that closes by itself to severe defects needing multiple surgeries in early childhood. The trajectory has changed dramatically over the last 50 years: the vast majority of children with CHD, including the most complex types, now survive to adulthood. The medical work has shifted from saving lives to supporting long-term physical, neurodevelopmental, and emotional outcomes.
