||Congenital heart defects (CHD), also known as congenital heart disease, are the most common type of birth defect and affect approximately 8 babies per 1,000 live births. According to the Center for Disease Control (CDC), approximately 4,800 babies in the United States are born with a congenital heart defect.
Congenital (meaning present from birth) heart defects are structural abnormalities of the heart, such as the heart walls, valves, veins, and/or arteries, which affect the normal flow of blood through the heart. CHDs can range in severity, from very mild to severe and life-threatening. Congenital heart disease is the leading cause of death in infants less than one year of age.
Depending on the severity of the heart defect, symptoms can be seen immediately or within a few days of birth while other mild defects may present with only minimal or no symptoms of heart issues. It is estimated that over 1 million children and adults are living with some type of CHD in the United States.
Many heart defects do not require any special type of treatment and may resolve on their own. More complex heart defects, however, may require medication, corrective surgery or heart transplantation.
Because some heart defects are not apparent immediately after birth, they can be missed. Approximately 280 babies per year are sent home from the hospital with an undetected heart defect. Even trained pediatric cardiologist can miss diagnosing a heart defect.
Some major heart defects can be seen on prenatal ultrasounds while others are detected after birth. After birth, a newborn
undergoes a physical assessment by both a registered nurse and physician in which the newborn’s color, heart rate and rhythm, respiratory rate, breath sounds and the presence of a murmur are evaluated. Some defects can be detected through physical assessments.
Pulse oximetry has also been shown to be a reliable screening tool for babies with the following seven critical congenital heart defects (CCHD):
Pulse oximetry is a simple, painless test that uses sensors to measure the amount of oxygen in the blood. An adhesive bandage with a red light (pulse oximeter) is applied to a baby’s foot and hand and the oxygen concentration is measured and displayed on the monitor. Low oxygen concentration is a sign of congenital heart disease.
The American Academy of Pediatrics defines the following as a positive pulse oximetry screening result requiring follow-up and more extensive testing:
- Any oxygen saturation measuring less than 90%. If the oxygen saturation is less than 90% at any point during the screening, there is no need to repeat the testing.
- Oxygen saturation less 95% in both extremities (hand and foot) on three separate measurements. Each of the three readings needs to be taken an hour apart from the previous reading.
- If there is a >3% absolute difference in oxygen saturation between the right hand and foot on three separate measurements. Each of the three readings needs to be taken an hour apart from the previous reading.
Any screening that is ≥ 95% in either extremity (hand or foot) with ≤3% absolute difference in oxygen saturation between the upper (hand) and lower (foot) extremity would be considered passing and the screening would end.
If the physical assessment and/or pulse oximetry screening results are positive, the AAP recommends that the primary care physician consult a pediatric cardiologist for additional testing. The following additional tests may be performed:
- Electrocardiography (ECG or EKG)
- 4-extremity blood pressure which compares the blood pressure reading in the right arm, left arm, right leg, and left leg.
The American Academy of Pediatrics, American College of Cardiology Foundation, and the American Heart Association recommend routine screening of all newborns before discharge from the hospital. Some physicians are leery about this recommendation since pulse oximetry results are not 100% accurate and can provide parents with a false sense of security. Unfortunately, certain defects are not apparent until the baby has left the hospital and the ductus arteriosis has closed.
Pulse oximetry screening guidelines recommend for newborns to be screened in the well-baby nursery after 24 hours of age and prior to discharge from the hospital. The advantages of screening include:
- Detection of other heart-related and non-cardiac conditions, such as persistent pulmonary hypertension.
- Testing is inexpensive and costs approximately $5 to $10 per infant.
- Screening can be completed within 1-5 minutes (unless repeat testing is required).
- The test is easy and does not inflict any harm on the baby.
- Supplies are readily available.
The disadvantages include:
- Discharge can be delayed to complete the screening, especially for those infants who require the entire 3 hours of testing.
- Screening can result in a false positive test which will add undue stress on the parents, incur additional expenses, and cause unnecessary testing. False positive results are common in higher altitudes; therefore, adjustments may need to be made.
- And finally, pulse oximetry screening may not detect all heart conditions and can give parents a false sense of security.
With adequate staff and parental education, nurses and doctors can learn to communicate the pros and cons of pulse oximetry testing to ensure parents understand the test, rationale for testing, and the limitations of such testing. Talk with your baby’s healthcare provider before your baby arrives to discuss the importance of pulse oximetry screening.
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