TGA is a heart defect that can be diagnosed by ultrasound before babies are born, typically after 18 weeks gestation during the 2nd or 3rd trimester. A provider may suspect a baby has TGA based on indications from an ultrasound, and can request a fetal echocardiogram, which is a detailed ultrasound of a baby’s heart.
Diagnosing TGA in babies before birth is important because they require special care soon after birth. Babies with TGA should be born in a high-risk birth center where there is access to neonatal and cardiology services at the time of delivery.
Babies who are born with TGA will show symptoms at birth or shortly after. Depending on how much mixing of red and blue blood is present through the ductus arteriosus, patent foramen ovale, and any ventricular septal defects, symptoms will vary in severity.
- Newborn pulse oximetry screening can help detect TGA by measuring the amount of oxygen in a baby’s blood. If oxygen levels are low, this can signal to the care team to perform further testing to assess for undiagnosed conditions such as congenital heart disease.
- Similar to prenatal testing, the most common test used to diagnose TGA is an echocardiogram.
- Other common tests used to help diagnose and assess babies with TGA include:
- Cardiac catheterization
- Chest X-Ray
Signs and symptoms of TGA
When babies are born with TGA, there is not enough oxygen getting out to their body. This can lead to severe symptoms, complications and death if left untreated.
Common signs of TGA:
- Cyanosis (bluish-tinted skin) caused by a low amount of oxygen getting out to the body
- Difficulty breathing
- Poor feeding
On average, Children’s Mercy sees around 10 babies per year with TGA.
Treatment for TGA begins shortly after birth. Babies with TGA will require monitoring in the neonatal intensive care unit (NICU) before surgery and will go to the pediatric intensive care unit (PICU) following surgery for close monitoring. Once the baby is stable, they will then go to our inpatient cardiac unit on 4 Sutherland.
Treatment options include:
Shortly after birth, a medication called Prostaglandin is given continuously to babies through an IV line. The purpose of this medication is to keep the patent ductus arteriosus (PDA) open and prevent from closing in order to allow for mixing of the red and blue blood, so that the body will receive some oxygen-rich blood. Babies may stay on this medication until they undergo surgery.
Babies with TGA will likely need oxygen after birth as well. If a baby has a low oxygen level or has difficulty breathing on their own, a breathing tube may be needed.
If the hole between the upper chambers of the heart (atrial septal defect) is not big enough after birth, a catheter procedure called an atrial septostomy may be needed to make the hole larger in order to allow for mixing of the red and blue blood. It is common for babies with TGA to need this procedure and is performed in a catheterization lab by cardiologists who specialize in interventional pediatric cardiology. This procedure is often performed sometime within the first few hours to days after birth, depending on the severity of baby’s symptoms and how big the atrial septal defect is.
Every baby born with TGA will require heart surgery in the newborn period, typically between the first 3 to 14 days after birth. The most common surgery with the best outcomes is the arterial switch operation. This operation involves switching the main arteries as well as the coronary arteries and large blood vessels, where the pulmonary artery connects to the right side of the heart, and aorta connects to the left side of the heart.