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Fetal cardiology

What we do

We are a leading centre for fetal cardiology and we helped pioneer this specialty in the UK. We are part of the Harris Birthright Centre and perform detailed fetal heart scans on pregnant women.

We perform fetal heart scans if:

  • a routine pregnancy scan has shown a possible problem with the unborn baby’s heart, or
  • either parent of the unborn baby has a medical or family history that may increase the risk of heart problems in their children.

We perform around 2000 scans a year. In most cases, we can reassure people that their unborn baby’s heart is normal. If an abnormality is found, we give you the information you need, discuss your options with you, and help plan for the pregnancy, birth, and beyond. This may include a full detailed scan of your unborn baby on the same day, if you wish. A number of fetal heart problems can be treated during pregnancy or immediately after birth. Where needed, we can perform surgery on babies while they are still in the womb.

If your unborn baby is found to have a minor heart condition, we will treat them jointly with your local hospital. If they need a heart operation soon after they are born, they will have their surgery at the Evelina London Children’s Hospital. Our consultants work at both King’s and the Evelina. Evelina patient leaflets are available for some conditions treated there.

If you are pregnant and think your unborn baby needs a specialised heart scan, please discuss this with your midwife.


We take part in research that improves diagnosis and outcomes for babies with heart problems. We will discuss our research with you if it is relevant to your treatment. To take part in a study or to find out more, ask a member of the team at your appointment. Research we are currently involved in includes:

  • ‘FIMOX’ , a study where we look at the effect of giving oxygen during pregnancy, and whether this can improve the diagnosis of fetal abnormalities.
  • iFIND, a project to improve pregnancy scanning by increasing its accuracy and the number of conditions it can detect.

Further advice and support


Second Floor, Fetal Medicine Research Institute, 16-20 Windsor Walk, SE5 8BB

Contact Details

Conditions we treat

We take for referrals from GPs, obstetricians, and midwives for detailed fetal heart scans. Reasons to refer to us include:

  • a routine antenatal scan has shown a possible fetal heart abnormality
  • an abnormal fetal heartbeat
  • congenital cardiac disease in either parent or in a sibling
  • diabetes mellitus, systemic lupus erythematosus or Sjorgren’s syndrome of the mother
  • the mother is on medication, for example, for epilepsy or depression
  • a scan performed in earlier pregnancy showed an increased amount of fluid behind the baby’s neck (raised nuchal translucency)
  • twin to twin transfusion syndrome
  • genetic syndrome in the baby. For example, Trisomy 21
  • other abnormalities have been detected in the baby.

Timing of fetal heart scanning

In most cases, a single detailed fetal heart scan is performed when the mother is 19 to 22 weeks pregnant. We do offer scans as early as 12 weeks for certain referral indications, for early diagnosis, and reassurance.

Follow-up scans are required:

  • if the first scan was performed at 12 to 18 weeks
  • and for some referral indications.

Fetal cardiac intervention

Most unborn babies who are found to need heart surgery have their operation after they are born. However we also perform life-saving and disease-modifying procedures on babies in the womb. We work with the Evelina London Children’s Hospital paediatric cardiology team to perform this surgery.

The three procedures we perform are:

  • balloon aortic valvuloplasty in critical aortic stenosis
  • balloon pulmonary valvuloplasty in pulmonary atresia with intact ventricular septum or critical pulmonary stenosis
  • perforation of the atrial septum in hypoplastic left heart syndrome with restrictive atrial septum.

What is required before referring a patient

Please supply clinical indication, estimated due date, relevant test results, and local obstetrician/midwife contact details.

Booking a patient at King’s

Routine Referrals

Email [email protected]

Emergency Referrals

Email [email protected]

For urgent (in the next 48 hours) appointments, call 020 3299 3246, choose option 3, then option 2.

Other Queries

Tel: 020 3299 8254

If you are a tertiary referrer and you would like to discuss a potential surgical referral, call the fetal cardiology team at the Evelina on 020 7188 2306.

See the Harris Birthright Centre page for other fetal medicine referrals.

Key Clinical Staff

Name Role
Ms Lou Reynolds Fetal Cardiology CNS
Dr Trisha Vigneswaran Consultant Paediatric & Fetal Cardiology
Mx Julie Williamson fetal CNS