This is a question we received from a mom who is pregnant with her second baby. Congenital heart defects (CHDs) are the most common types of birth defects and if you already have a child with a CHD, you may wonder if your second child will have the same defect. The answer, though, is not a simple “yes” or “no.”
We don’t know the cause of most congenital heart defects. For some babies, their heart defects were caused by changes in their chromosomes or genes (which are passed from parents to children). Researchers have found about 40 gene changes (also called mutations) that cause heart defects. About 30 in 100 babies (30 percent) with a heart defect also have a chromosomal condition or a genetic condition. So if you, your partner or one of your other children has a congenital heart defect, your baby may be more likely to have one, too.
But CHDs are also thought to be caused by a combination of genes and other factors, such as things in your environment, your diet, any medications you may be taking, and health conditions you may have. Conditions like diabetes, lupus, rubella and even obesity can play a role in causing CHDs.
So what is your risk?
The chance of having another child with a CHD depends on many factors. It is best to meet with your health care provider and a genetic counselor who can better assess your risk. A genetic counselor is a person who is trained to help you understand how genes, birth defects and other medical conditions run in families, and how they can affect your health and your baby’s health.