What is a Congenital Heart Defect?
Congenital heart defects develop before the baby is born, and may be caused by a combination of genetics and environment. These defects develop in the very beginning of pregnancy (before many mothers know they are even pregnant), when the baby’s heart is just beginning to form. Congenital heart defects may affect the heart’s shape as well as function, causing malformation of arteries and veins or issues with fetal heart rates.
While not all heart defects require immediate emergency intervention, these diagnoses can be stressful for families, and it can be overwhelming to plan for a birth in the face of a heart condition. Thankfully, there are ways to detect and treat fetal heart defects and improve the chances of a healthy, normal birth.
Early detection and screening can help parents decide where to deliver, develop care plans and strategies, and get the support they need. For Phoenix area high-risk mothers, Valley Perinatal Services provides care and education to help improve the outcome for families facing fetal heart defects.
What are the Risk Factors for a Fetal Heart Defect?
There is no known cause for most fetal heart defects, and nothing you do or don’t do can eliminate the risk completely. However, there are factors that increase the risks for certain types of heart problems.
These risk factors include:
- Certain medical conditions or illnesses in the mother, including obesity, diabetes, lupus, rubella, and phenylketonuria.
- History of congenital heart problems or heart disease in the baby’s immediate family.
- Chromosomal conditions that are likely to appear alongside congenital heart defects, including Down syndrome, Turner syndrome, Noonan syndrome, Velocardiofacial syndrome, and Alagille syndrome.
- Usage of certain medications that have been linked to fetal heart defects.
While not all heart conditions can be prevented, there are ways to lower the risk. You should take folic acid and meet with a perinatologist for guidance before and during pregnancy.
Diagnosis and Screening of Fetal Heart Defects
If an irregular heartbeat is detected during standard pregnancy care, the Ob/Gyn will likely request further testing to check for heart defects. While a regular ultrasound provides an overview of the baby’s health, more specific tests are used to detect and assess fetal heart defects.
Here are some of the most common tests used to gather more information.
Like an ultrasound, an echocardiography uses sound waves to create a visual image of the heart and all its structures. This allows the doctor to diagnose defects related to the heart’s structure. They are generally performed between the 18th and 24th week of pregnancy.
Due to it being low-risk and relatively non-invasive, echocardiography is one of the most common tools for following heart problems and developing treatment plans over time.
Also called an EKG, this test records the heart’s electrical activity. This test can monitor how fast the heart beats, how regular the rhythm is, and the strength and timing of electrical signals in the heart. This information can help diagnose heart problems like enlarged chambers.
EKGs are performed on infants by placing small stickers (electrodes) onto the child’s chest, arms, and legs. Wires attach these stickers to the EKG machine and allow doctors to see electrical activity of the heart.
Cardiac catheterization is a medical procedure often used to diagnose and even treat some heart conditions. A long, thin tube is placed into a vein in the groin, neck, or sometimes arm, and is used to inject a special dye. It is a procedure performed after the baby is born.
This dye is visible on X-ray images and allows a doctor to see how blood flows through the heart and blood vessels. This procedure can be used to determine pressure, oxygen levels, and how and if blood is mixing between sides of the heart. This procedure can also be used to repair some heart defects. Recovery time is minimal for most patients.
X-rays are another method doctors use to view structures of the heart. They can show whether a heart is enlarged and can be used to detect whether a baby’s lungs have extra fluid or blood flow, which could indicate a problem.
In this test, which occurs after birth, a sensor is attached to the baby’s finger or toe and monitored by a computer. This test provides doctors with an estimation of how much oxygen is in the blood and could suggest a problem with the heart or lungs.
Physical exams involve looking at the outside of the body for signs of illness or fetal heart defects. The doctor will likely listen to the heart and lungs with a stethoscope to check for fluid or other problems.