If you have had a child affected by a complex heart problem, the thought of future pregnancies will inevitably be a scary prospect. Making the decision whether to try again is a complex one, coloured by the painful memories of what happened in the previous pregnancy or at birth when the diagnosis of a cardiac condition was made.
Although we know from research and experience that if you have had a child with a congenital heart condition, there is a small increased risk in future pregnancies, by far the most likely outcome is that you will have a child with a normal heart.
Your own individual recurrence risk will be given to you by your medical team, but the range could be anything from 2-3% to 8%. The factors influencing this include the exact nature of the condition your previous child had and your individual family background. However, it may help to bear in mind that even if the recurrence risk is 8%, it means that you have a 92% chance of your baby’s heart being normal next time, and even if there is a problem, it would not necessarily be the same, or as severe, as your previous child.
Whilst statistics such as these are given to reassure you and help you make plans for the future, we know that when you have had a child with a congenital heart condition, it is hard to believe that it will not happen again.
Most parents will want to know if there is anything they can do to reduce the risk of recurrence. Whilst as yet, the causes of single ventricle heart disease are not known, there are a few simple things that parents can do to keep themselves healthy and therefore give their baby the best chance.
- Eat a good balanced diet including foods rich in folic acid, e.g. fruits, green leafy vegetables, lentils, chickpeas, some cereals and bread.
- Cut down on the intake of caffeine to reduce the risk of miscarriage.
- Reduce and, if possible, stop smoking prior to conception. Smoking can affect the fertility of both men and women and may mean it takes longer to conceive.
- Reduce and if possible stop drinking alcohol prior to conception. Alcohol too can affect both men’s and women’s fertility.
- Take 400 micrograms of folic acid once a day ideally for three months prior to conception and for the first twelve weeks of the pregnancy. This is thought to reduce the risks of neural tube defects such as spina bifida.
- Exercise regularly to maintain a reasonable level of fitness.
Facing the emotional impact of a further pregnancy
No one can take away the anxiety which the thought of a future pregnancy brings. Sometimes it might be helpful for parents to see their obstetrician or GP prior to embarking on a pregnancy, to talk through some of the issues surrounding how a subsequent pregnancy would be managed and what support could be given. For some parents, making a decision to try again can be helped by talking to other parents who have had an affected child and who have had a further successful pregnancy. Little Hearts Matter can put parents in touch with one another and these contacts can be valuable sources of support both prior to and during a pregnancy.
The booking scan
The booking scan, usually carried out by about 12 weeks of pregnancy, will hopefully be a positive affirmation that so far all is well and that the first hurdle of early miscarriage is past. Seeing the baby on the screen can bring a mixture of emotions as hopes and aspirations for this new baby combine with memories of scans in the previous pregnancy.
Further routine tests will also be offered to look for the risk of Down’s syndrome and the general size and growth of the baby will be measured.
All parents of a child with a congenital heart condition should be given the opportunity to have a specialist fetal cardiology scan if they want one. This can be arranged as part of the booking process.
How early in pregnancy can heart abnormalities be detected?
Unfortunately, congenital heart conditions can only be detected by a detailed ultrasound scan and traditionally scanning in pregnancy for the detection of heart abnormalities has been around 20 weeks of pregnancy when the heart is the size of a walnut.
As scanning technology and expertise of those carrying out the scans has improved, it is now possible in some fetal medicine centres to offer an initial heart scan at around 14 weeks.
Clearly for parents who have had a previously affected child, any reassurance which can be given earlier in pregnancy is beneficial. Parents would need to talk to their obstetrician to find out whether early cardiac scans are available in their area.
What can be detected at this early scan?
The heart at 14 weeks is about the size of a pea and therefore it is not possible to visualise all the structures in the heart in sufficient detail to reassure parents that the heart is completely normal but it is possible to detect major abnormalities. The team will also look for other indications that the baby may have a problem, for example, the nuchal translucency (fluid filled space at the back of the baby’s neck).
If all of the tests are normal, it is likely that the heart will be normal although a further scan will be arranged around 20 weeks for added reassurance.
Why is a measurement of the nuchal translucency carried out?
It is known that there is an increased risk of the baby having a heart abnormality if the measurement of the nuchal translucency is larger than it should be for the number of weeks of pregnancy.
An increased nuchal translucency measurement is also a marker of increased risk of chromosome abnormalities such as Down’s syndrome. If this was found to be the case, the clinician would discuss with parents whether they would like further tests to check whether the baby’s genetic make-up is normal.
What happens if an abnormality is found?
In the rare case that the fetal medical team detect or suspect that there is a problem with the structure or function of the heart they will organise for further scanning and other tests to be conducted.
Throughout the process expectant parents will be involved in discussions about the baby and any treatment path that is suggested for the baby and mother’s care.
What other tests are offered in pregnancy?
If there are indications that there may be an abnormality in the heart, other organs, growth or development of the baby, further tests will be offered to seek further information.
Chorionic Villus Sampling takes a sample from the developing placenta and is carried out at around 11 weeks. The procedure carries a risk of miscarriage of about 1 in 75 and the first part of the result (the PCR test) which looks at the three more common chromosome differences, including Down’s syndrome is usually available in three to four days. The full results are usually available within three weeks.
Amniocentesis takes a sample of amniotic fluid from around the baby and is carried out at around 15 – 16 weeks. The risk of miscarriage is about 1 in 100 – 150 and the first part of the result (the PCR test) which looks at the three more common chromosome differences, including Down’s syndrome is usually available in three to four days. The full results usually take between two to three weeks.
It is very important that parents are given adequate opportunities to ask questions and voice their concerns with their doctors or midwives so that they ultimately feel comfortable with the decisions they make.
Whichever antenatal tests parents choose, waiting for the results will be an anxious time. Many parents choose to wait until they have had the reassurance of a normal result before telling other people about the pregnancy and this can be quite a strain, particularly if they have opted for a later test.
It is important to remember that most future pregnancies (and most importantly the new baby) will have no complications and will be born without any problems.
The rest of the pregnancy
Most parents who have had previous problematic pregnancies, talk about the heightened sense of anxiety which remains throughout the pregnancy and how they worry more about other things going wrong, such as the baby not growing, not moving or being stillborn. This is a completely normal response to what has happened in the past and it is often helpful to talk to others who have had similar experiences, as they will understand this mixture of fear and hope.
Midwives and doctors need to be aware of the increased anxieties that parents will feel and allow time to voice concerns.
Most parents with no previous problems view the birth with some sense of trepidation. For parents who have memories of their previous birth and what they had to face following it, the birth will be a further time of extreme anxiety and dread that something might go wrong, even at this late stage. It is not until the baby is finally in their arms, having been checked over and pronounced healthy, that parents will gradually begin to relax and look towards the future.
To embark on a future pregnancy is a courageous undertaking, but for most couples it is well worth the emotional rollercoaster ride it entails.
This article has been written by taking advice and information from Ruth Kirchmeier, Midwife in Fetal Medicine and Dr Anna Seale, Fetal Cardiologist at Birmingham Women’s Hospital, Sherrida Rollings, Paediatric Sister and former Fetal Cardiology Counsellor and Professor Simpson, Fetal Cardiologist at the Evelina Children’s Hospital.