A congenital heart defect (CHD) is the most common type of birth defect. It is estimated that 2 to 3 million people in the United States have a CHD.
Over the last few decades, treatments for CHDs have improved—meaning more children born with a CHD are growing up to have children of their own.
If you have a CHD, you might wonder what the risk is for your child to also have a CHD. You might also wonder whether pregnancy will affect your health. These are very important questions to discuss with your congenital cardiologist and perhaps other specialists, such as a maternal-fetal-medicine specialist and a geneticist or genetic counselor.
What causes a congenital heart defect?
CHDs are caused by genetics, the environment, or a combination of both. Some known genetic causes include:
- Chromosome abnormalities: Extra or missing chromosomes.
- Gene mutation: A change to the DNA sequence or order that makes up a gene.
About genetic testing:
There are two types of tests used with genetic testing: chromosomal and DNA. Recent advances in these tests have made it more possible to find the genetic cause of CHDs for many patients. Sometimes, however, a genetic change cannot be identified, but the cause can still be genetic.
How to reduce your baby’s risk of a congenital heart defect:
If you have a CHD, your baby has a higher risk of being born with a CHD. In fact, there is about a 5% chance your child will have a CHD, too. A geneticist or genetic counselor can help you determine if genetic testing might be helpful for you prior to becoming pregnant.
You might be asking yourself:
- What can I do to lower my baby’s chance of being born with a CHD?
- How might I be able to improve my baby’s outcome if he or she has a CHD?
These are important questions to ask your medical care team, but some research suggests taking folate prior to conception and during pregnancy may decrease the risk of a CHD.
How a congenital heart defect is diagnosed in an unborn baby:
A CHD can be diagnosed very early in pregnancy (around 18 to 20 weeks) via an ultrasound of the baby’s heart, called a fetal echocardiogram.
If you have a CHD caused by a genetic change, your maternal-fetal-medicine specialist can perform either an amniocentesis or chorionic villus sampling to determine whether your unborn baby has the same genetic change. Both of these tests are done by inserting a needle into the womb to get a small tissue sample for testing.