Fetal Heart Defects


When a woman becomes pregnant, her baby’s heart is one of the first organs to form. It starts out as a tube, and then twists and separates to form the heart and heart valves. In about one percent of babies born in the U.S., something happens that interferes with this process. As a result, the fetus develops a congenital (present at birth) heart defect.

Congenital heart defects are the most common type of birth defect. Usually, the cause is not known, but the risk may be higher if:

  • The baby’s mother, father or sibling has a congenital heart defect.
  • There is a family history of diseases known to affect the heart.
  • The baby has been diagnosed with a genetic disease characterized by an abnormal number of chromosomes, as in Down syndrome.
  • The mother has taken medications known to cause congenital heart defects.
  • The mother has specific health problems such as type 1 or type 2 diabetes, an autoimmune disease such as lupus, or certain infections such as measles while pregnant

Diagnosing Fetal Heart Defects

There are many types of congenital heart defects. Some heart defects are not evident until the baby is born, but others may be detected during pregnancy with an ultrasound. Should a prenatal ultrasound indicate your baby may have a heart defect, or if you have risk factors, your obstetrician will most likely order a test called a fetal echocardiogram to examine your baby’s heart before birth. A fetal echocardiogram (echo) is a detailed ultrasound exam that takes images of the baby’s heart. A fetal echo may be performed by the maternal fetal medicine specialist or a pediatric cardiologist.

Treating Fetal Heart Defects

If the echocardiogram confirms that your baby has a heart defect, our multi-disciplinary team will recommend the best treatment options to you and your family. Your Mercy care team may include maternal and fetal medicine specialists, pediatric cardiologists working in collaboration with pediatric cardiovascular surgeons (when necessary), Fetal Care Team coordinator, neonatologists, nurses, genetics counselors and other professionals, all dedicated to your baby’s heart care.

Your pediatric cardiologist will explain how the defect affects your baby’s heart and what to expect from treatment. 

Mild defects may need nothing more than monitoring to ensure they don’t cause problems, and some may correct themselves before the baby is born. In some cases, babies with congenital heart defects may need surgery or other treatment at the time of birth or within a few days or weeks. Very rarely, a fetal heart defect will need to be surgically repaired via intrauterine surgery before the baby is born.

If more specialized care is required for your newborn, our Neonatal Intensive Care Units (NICU) offer advanced, round-the-clock care for premature or critically ill babies.

We know it can be upsetting to hear that your baby has a heart problem. Know that your entire Mercy team will provide expert, loving care and support to get you both on the road to health.

Connect to Mercy Experts

View More View More