FAQs

How is Newborn Screening for CCHD done?

Your baby will be screened for birth defects of the heart before he or she leaves the nursery. This usually happens after 24 hours of age, unless the baby is discharged early, in which case it will happen just before discharge. The screen is done by using a pulse-oximeter, which measures the amount of oxygen in the baby’s blood. Babies who have certain heart problems will have lower than normal blood oxygen levels. The pulse-oximeter sensors are usually placed on the baby’s hand and foot, measurements of blood oxygen levels and heart rate are collected and evaluated, and the parents are informed right away if there is a problem. In some cases, one or 2 repeat screening tests will be needed before a final results can be communicated. Don’t hesitate to ask for results and more information before you go home if you have questions about the screening results.

What conditions are identifiend through pulse oximetry screening? What are the limitations of pulse oximetry screening?

There are many kinds of birth defects of the heart. Those that can be found by pulse-ox screening account for only 1 out of 4 of the possible heart defects than can be present at birth. This is important, because it means that if your baby has signs of possible heart problems like those noted above, even if he or she had a normal pulse-ox screen, the baby needs to be promptly evaluated by a doctor to see if an undetected heart problem exists. The kinds of heart problems detected by pulse-ox screening all lead to lower than normal amounts of oxygen in the blood.

These include:

Hypoplastic left heart syndrome - severe under-development of the lower left, pumping chamber of the heart. Several heart valves are also incorrectly formed.

Pulmonary atresia with intact septum - the pulmonary valve between the heart and the lungs is not formed correctly and doesn’t open to let blood move from the heart to the lungs to pick up oxygen. IN this case, there is no hole between the right and left sides of the heart

Tetralogy of Fallot - a combination of pulmonary atresia (above), a hole between the 2 lower chambers of the heart, abnormal position of the biggest artery (aorta) and bigger and more muscular than normal right, pumping chamber (ventricle) of the heart

Total anomalous pulmonary venous return - normally, the 4 pulmonary veins carry blood from the lungs back to the left upper chamber of the heart, where it is then sent to the left pumping chamber (ventricle) and to the body. With total anomalous pulmonary venous return, the pulmonary veins connect to other veins that lead to the right side of the heart, so the good, oxygen-carrying blood gets sent back to the lungs instead of to the body.

Transposition of the great vessels - the 2 main blood vessels that carry blood away from the heart are attached incorrectly. The pulmonary artery is attached to the left lower (pumping) chamber of the heart instead of the right, and the aorta is attached to the right lower (pumping) chamber of the heart instead of the left. Because of this switch, good, oxygen-carrying blood does not get to the body where it is needed.

Tricuspid atresia - absent or poorly developed valve between the 2 right chambers of the heart, usually with a hole between the upper 2 chambers of the heart and smaller than normal right, lower pumping chamber of the heart.

Truncus arteriosus - presence of a single large blood vessel carrying blood away from the heart instead of the normal 2 (pulmonary artery and aorta). This results into much blood going to the lungs to pick up oxygen, making breathing difficult.

A number of other heart problems may be detected by pulse-ox screening:

Coarctation of the aorta - narrowing of the main artery (aorta) that flows out of the heart to the body, causing the heart to work too hard to pump blood to the body.

Double outlet right ventricle - attachment of both the pulmonary artery and the aorta to the right pumping chamber of the heart, leading to too little oxygen getting to the body. Babies with this also have a hole between the 2 pumping (lower) chambers of the heart.

Ebstein anomaly - leaky valve between the 2 right chambers of the heart, often with a hole between the 2 upper chambers of the heart

Interrupted aortic arch - an interruption, break or disconnection of the aorta above the heart. Blood must flow to the body through a different route, usually through a structure called the ductus arteriosus which normally carries blood during fetal life and then closes off after birth.
Single ventricle - this include a number of birth defects of the heart ion which there is only one lower pumping chamber of the heart that is working well enough to pump blood to the lungs and/or body. It includes a number of the conditions listed above.

What will happen if my baby's pulse-ox screen is outside of the expected range?

If your baby’s pulse-ox screening is abnormal, the next step is an echocardiogram, or ultrasound specifically of the heart to look for changes in the structure of the heart. Not every baby who has an abnormal pulse-ox screen will have problems found on the echocardiogram. Many birthing hospitals can do pediatric echocardiograms on site, but if that is not possible, the baby may need to be taken to a regional facility for the heart studies. A visit to a pediatric cardiologist may also be recommended and the baby’s pediatrician should be notified about the concerns raised by screening. If this follow-up testing shows problems with the baby’s heart, the parents will be informed about the problems and assisted as essential care is provided for their child.