Congenital heart defects
What causes congenital heart defects?
New mothers often wonder if they did anything to cause their baby’s CHD. It’s important to remember that in most cases, CHD has no known cause. Most of the time, there is no identifiable reason as to why the heart defect occurred. However, some at-risk groups include:
- women who take anti-seizure medication while pregnant
- women who take lithium while pregnant
- women who have phenylketonuria but do not adhere to the special diet necessary
- women who have insulin-dependent diabetes or lupus
- women who contract rubella while pregnant
- There is approximately an 8-10% risk that a mother with a congenital heart defect (CHD) will have a baby with some type of CHD, but not necessarily the same defect as the mother. High risk prenatal monitoring of the mother and baby is recommended.
If you fall into any of these categories, it’s important to talk to your doctor while pregnant.
What are some types of CHD?
Several CHDs are detected and treated early in infancy.
patent ductus arteriosus
- blood bypasses lungs, preventing oxygen to circulate
tetralogy of fallot
- four simultaneous heart defects
transposition of the great vessels
- blood from the left and right sides of the heart mix together
coarctation of the aorta
- pinched aorta
- the right or left side of the heart is incompletely formed
- heart valve problems
What are some symptoms of CHD?
Symptoms of CHD in infants and children include:
Are CHDs genetic?
About 1 percent of all children are born with CHD, but the risk increases if either parent, or a sibling, has CHD.
- If you’ve have one child with CHD, your second child has a 1.5 to 5 percent chance of having a CHD.
- If you have two children with CHD, your third child has a 5 to 10 percent chance of having CHD.
- If the mother has a CHD, the child has a 2.5 to 18 percent chance of having CHD.
- If the father has a CHD, the child has a 1.5 to 3 percent chance of having CHD.
If you have a CHD, we recommend that you speak with a genetic counselor or genetic specialist at Children’s before becoming pregnant. In families with a CHD either in the parents or offspring, a fetal echocardiography can be performed in the second trimester to determine the presence of major heart defects.
Other causes of CHDs
- Chromosomes are the structures in your cells that contain your genes, which determine traits such as eye color and blood type. Usually there are 46 chromosomes in each cell of the body. Having too many or too few chromosomes results in health problems and birth defects.
- Five to 8 percent of all babies with CHD have a chromosome abnormality.
- There are a number of chromosome abnormalities associated with congenital heart defects, including:
When a gene is mutated, a number of health problems may occur. Several health problems with one genetic cause are often referred to as a syndrome. Some of the genetic syndromes associated with a higher incidence of heart defects include:
- Marfan syndrome
- Smith-Lemli-Opitz syndrome
- Ellis-van Creveld
- Holt-Oram syndrome
- Noonan syndrome