Many families planning to have a child having previously had a child with the diagnosis of a single ventricle heart, are worried that there are risks that the condition will happen again.
Throughout the country, medical teams offer specialist scanning to parents in families where a complex heart condition has been seen in a previous child.
Fortunately the chance of having a heart-healthy child far outweigh the risk of having another child with a heart problem but as there is a small risk, specialist scanning will be offered. This should happen automatically with either your GP or obstetric team offering parents the opportunity to go back to see the cardiac team that were involved at previous diagnosis. This usually happens as part of a fetal medical service in each region. The fetal cardiologist works within a team at the cardiac unit and within the fetal service. If expectant parents are not offered the service they can request that they see the specialist team.
Here the Guy’s and St Thomas’ team at the Evelina London Children’s Hospital explain the service that they offer.
The fetal cardiology department at Evelina London offers early screening for women with a family history of a single ventricle heart condition.
What does family history mean?
Either you or your partner have had a diagnosis of a single ventricle heart condition, made in a previous pregnancy or after birth. If either parent has undergone treatment for a single ventricle heart condition then this is an indication.
We offer scans where there is a history of the condition in a previous child or one of the parents or if one parent is affected. Scans are not typically offered if a single ventricle heart condition has affected a more distant relative.
In the medical literature some series have reported a recurrence rate of up to 8% for HLHS (8 out of 100 subsequent pregnancies) and slightly less for other single ventricle heart conditions. Each family will be given their own risk of reoccurrence depending on their family experience.
Publishing data from our own unit has shown a 2-3% risk of congenital heart disease, including HLHS where a previous pregnancy has been affected. If there is a recurrence, this tends to be a left heart type of condition but not necessarily as severe as HLHS. To put this in context, the risk of CHD in any baby is eight per thousand (0.8%) of whom half will require surgery or catheter intervention.
What is a fetal cardiac scan?
During pregnancy women are offered an anomaly scan at approximately 20 weeks of pregnancy at their local hospital. When cardiac concerns are identified a referral is made to our department. We are a team of fetal cardiologists, fetal cardiac sonographers and fetal cardiac nurse specialists.
When a family history is identified we are able to offer early scans from 14 weeks of pregnancy.
What steps can you take if you have a family history?
- Early booking with your local midwifery team is advised. Updating your midwife on your family history of HLHS is very important. Most local teams are aware that early scanning is available. In some cases you may need to be ‘proactive’ by asking for a referral.
- Who can make the referral?
This will need to be completed by your midwife or GP. You cannot self refer.
Our team will support you during your scan. We appreciate and respect the anxiety that comes with future pregnancies when you have a family history of a complex heart condition. It is always helpful to have your partner, friend or family member accompany you to your appointment.
The scan will be done by one of our specialist sonographers and takes approximately an hour to complete. This is because your baby’s heart is very small at 14 weeks gestation and your baby will be moving around. When the scan is complete, it will be reviewed by one of our fetal cardiology consultants and you will be provided with feedback.
If your family has a history of a genetic condition you will be offered condition scanning and possibly some tests of the baby’s blood or amniotic fluid around the baby.
If the scan at 14 weeks proves normal we will still recommend at least one scan later in pregnancy to check growth of left heart structures as the baby gets bigger. If prenatal scans are normal we do not normally advise cardiology referral after birth unless there are clinical concerns.
Judy Tenenbaum, Fetal Cardiology Clinical Nurse and Professor John Simpson, Professor of Paediatric and Fetal Cardiology Specialist.