How the diagnosis of single ventricle heart disease is made
There are two main opportunities for a diagnosis of complex heart disease to be made – either before or after birth.
Antenatal diagnosis
In many cases it is now possible to make a diagnosis of a single ventricle condition when a pregnant woman undergoes her 16 – 20 week ultrasound scan. Scans before this stage of the pregnancy are unlikely to detect problems because the baby’s heart, lungs and other organs are not big enough to be seen clearly.
A sonographer (the member of staff who scans mothers to look at the baby) will be looking to see that the baby’s heart has four chambers, and two major crossing blood vessels leaving the heart. If there is any doubt that the baby has a normal heart or other organs the sonographer will seek a second opinion from the obstetrician or fetal medicine doctors (doctors who specialise in looking at unborn babies).
If a problem with the heart is seen clearly, the obstetric team will refer the family to a specialist in this field, a fetal cardiologist (a heart doctor who specialises in looking after unborn babies). If a complex condition is confirmed, the cardiologist and the obstetric team will talk to the family about the diagnosis and the possible treatments. They will offer further tests, such as amniocentesis, to see if the baby has any unseen problems with their genetic picture (to see if the blueprint of the baby has a fault – for example, something like Down’s syndrome). For more information on antenatal tests speak to your midwife.
Once all of the tests have been completed the family will be given the opportunity to discuss the future for their child. The team will support the family whilst they make their decision either to continue with the pregnancy or to end the pregnancy through termination.
Most babies with a single ventricle condition grow well in their mother’s womb. They are usually born between 38 and 40 weeks of pregnancy. It is only after birth, once their fetal circulation changes (see Fetal Circulation) that their defects begin to affect their bodies.
For more information on antenatal diagnosis refer to Antenatal Information.
Postnatal diagnosis
As long as the ductus arteriosus remains open, it is often difficult to detect that a newborn baby has a problem with its heart. (See Fetal Circulation).
As the ductus arteriosus closes the baby will become breathless and sweaty, sleep more and drink less milk. This can happen while the baby is still in hospital and may be detected by the midwife or doctor as they do their post-delivery checks or within a few days of going home when the midwife or health visitor should notice that the baby needs to see a doctor.
Once the baby has been referred to a paediatrician (baby doctor) tests will be done to try and find out what is causing the problem. Medicine called Prostaglandin will be given to the baby to try and keep the ductus arteriosus open, as this will keep the baby alive until treatment decisions can be made. (See Fetal Circulation).
The baby will be transferred with a medical team to the nearest hospital that treats congenital heart defects. Here the baby will have an ultrasound scan (echocardiogram or echo) similar to the scans done in pregnancy. The specialist heart team will be able to see what the heart looks like and will be able to make a diagnosis.