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Newborn Screening for Congenital Heart Disease.

According to the American Academy of Pediatrics, approximately 18 out of every 10,000 babies are born with a critical congenital heart defect (CCHD). CCHD is life threatening and requires intervention in infancy. However, CCHD is not always detected prenatally or upon exam in the nursery. As a result, some infants with CCHD are discharged from the nursery to home, where they may quickly decompensate.

To improve the early detection of CCHD, the Secretary of Health and Human Services (HHS) recommended that CCHD screening be added to the uniform newborn screening panel.

Listen as Caroline Lee, MD., Washington University pediatric cardiologist at St. Louis Children's Hospital and Director, Fetal Heart Center, discusses the guidelines for newborn screening for congenital heart disease.
Newborn Screening for Congenital Heart Disease.
Featured Speaker:
Caroline Lee, MD
Caroline Lee, MD is the Director, Fetal Heart Center, and a Washington University pediatric cardiologist at St. Louis Children's Hospital. She specializes in echocardiography and fetal echocardiography. Dr. Lee is happy to provide a second opinion on any heart disease diagnosis or heart disease treatment recommendation your child has been given.

Learn more about Caroline Lee, MD 

Transcription:

Melanie Cole (Host): According to the American Academy of Pediatrics approximately 18 out of every 10,000 babies are born with a critical congenital heart defect. This can be life-threatening and requires intervention in infancy. However, it’s not always detected prenatally or upon exam in the nursery. My guest today is Dr. Caroline Lee. She’s the Director of the Fetal Heart Center and a Washington University Pediatric Cardiologist at St. Louis Children’s Hospital. Welcome to the show, Dr. Lee. Tell us about some of the rationale for screening for critical congenital heart defects.

Dr. Caroline Lee (Guest): Well, thanks, Melanie. As you mentioned, congenital heart defects are the most common birth defect and are a leading cause of infant mortality. Many of these defects can be detected prenatally by fetal ultrasound. However, in our experience, over half of those defects are not detected prenatally. That relies on detection after birth which can be difficult in infants who can appear quite well while they transition in the first 24-48 hours of life. The rationale behind pulse oximetry screening is to hopefully detect abnormalities in an infant’s oxygen level that may alert the medical staff that there is a critical congenital heart defect.

Melanie: Let’s classify those heart defects into some categories to help better understand the problems the baby might experience.

Dr. Lee: Critical congenital heart defects are those that are on the more serious end of the spectrum. Those are ones that usually will require intervention, either surgery, open-heart surgery, or cardiac catheterization within the first year of life. Critical heart defects can lead to organ injury and even death if not diagnosed soon after birth. Those include diagnoses such as Transposition of the Great Arteries, Tetrology of Fallot, Hypoplastic Left Heart Syndrome, Tricuspid Atresia, Truncus Arteriosus, Pulmonary Atresia with Intact Ventricular Septum, Total Anomalous Pulmonary Venous Return. These are among other defects as well.

Melanie: So if the asymptomatic infant fails the pulse ox screening, what’s the likelihood that they have this or some other serious disease that might be present?

Dr. Lee: That’s a good question. There are other reason that a baby may not pass a pulse oximetry screen. In order to be considered a pass, in our system – in our health system, the infant would need to have a pulse oximetry reading of at least 95% in the right hand and foot and have less than a 3% difference between the right hand and foot measurements. If they do not meet this criteria and they are retested one or two other times to confirm that they do not pass, it can mean that there is a critical congenital heart defect, but it can also help identify babies with other causes for low oxygen levels, and those other causes include infection, respiratory diseases, such as pneumonia or pulmonary hypertension, and even other heart defects that are not considered critical. With this pulse ox screening, we found that in addition to critical heart defects being detected, there are actually more often non-critical heart defects that are being discovered as well – other reasons.

Melanie: Dr. Lee, which babies should be screened?

Dr. Lee: Well, since 2013, in the states of Missouri and Illinois, it has been legislated that there should be universal pulse oximetry screening for all newborns. All newborns after 24 hours of age should undergo this screening test.

Melanie: So then when we’re talking about those babies getting the screening tests, when should the screening begin, after, or before discharge?

Dr. Lee: It should be done before discharge and again after 24 hours, which allows the baby to transition from the fetal circulation to the newborn circulation and it allows time for the ductus arteriosus to close. That is a fetal vessel that usually goes away within the first day or two of life and in critical heart defects, can be necessary to avoid hemodynamic compromise, so we do wait after 24 hours to give that time for the ductus arteriosus to start closing, which then may help reveal a lower oxygen level.

Melanie: And where should the screening occur?

Dr. Lee: Screening occurs in the newborn nursery by trained staff, hopefully in a quiet area with the infants awake, calm, quiet, and it should be performed on the right hand of the infant – a measurement obtained on the right hand, and also on one foot.

Melanie: Do you test them one right after the other?

Dr. Lee: Yes, it should be done pretty soon right after the other to get accurate measurements in a similar space and then if oxygen is less than 95%, or if there’s greater than 3% difference between the right hand and foot’s reading then it should be repeated.

Melanie: Are there any modifications if someone is at high altitude, or what about babies that are born at home?

Dr. Lee: That’s a great question. It has been shown that infants at high altitude have a slower decline in their pulmonary vascular resistance, which means that their transition period is longer, so they may be more prone to false positives. Fortunately, in the St. Louis area, we are not in a high altitude area, but that has been shown in reasons like Denver and other high altitudes to cause more false positive readings as well. And as for home births – that also is a good question – how to capture all of those babies and effectively screen those babies. I know, at least in the State of Missouri, they’ve been working on ways to ensure that midwives and those that do home deliveries are adequately trained to go out and screen these babies.

Melanie: And what about premature infants?

Dr. Lee: Premature infants who are often in the newborn ICU are often on continuous monitoring of their oxygen saturations or at least routine O-2 monitoring. They also undergo screening in that way.

Melanie: So then speak about what a Pediatrician would do if there’s been a failed screen.

Dr. Lee: They should immediately evaluate and assess the baby. And again, signs can be subtle. A baby may not have a murmur. A baby may not appear dusky or cyanotic, obviously. For that reason, an echocardiogram should be performed, and the echocardiogram should be interpreted by a Pediatric Cardiologist. Depending on those findings, or if echocardiogram services are not available at the local hospital, then it will be necessary to transfer the infant to a tertiary care center to have that echocardiogram performed and further medical assessments.

Melanie: What would you like to tell other Pediatricians about the importance of this newborn screening for congenital heart disease?

Dr. Lee: It is important that newborn screening be done routinely by well-trained personnel because it can identify, and be a life-saving measure to find babies who have either critical congenital heart disease or as we mentioned before, other disease states such as infection or respiratory disease that may cause them hemodynamic compromise.

Melanie: And then tell us about your team, Dr. Lee. Why is St. Louis Children’s Hospital so great to work with?

Dr. Lee: The Heart Center at Children’s Hospital in Washington University is a multidisciplinary team consisting of Cardiologists, Cardiac Surgeons, Cardiac Anesthesiologists, Cardiac Intensive Care Unit Attendings and all sorts of ancillary staff as well. We have a representation of all of the Cardiac Subspecialties, whether it be an echocardiography, electrophysiology, cardiac catheterization, heart failure, transplants. Regardless of the type of cardiac issue an infant or a child might have, we have a diverse team that is well-equipped to care for any child with pediatric heart disease.

Melanie: Thank you, so much, Dr. Lee, for being with us today. A physician can refer a patient to St. Louis Children’s Hospital using the Children’s Direct, a 24-hour physician access line. That number is 800-678-HELP, that’s 800-678-4357. You’re listening to Radio Rounds with St. Louis Children’s Hospital. For more information on resources available at St. Louis Children’s Hospital, you can go to StLouisChildrens.org, that’s StLouisChildrens.org. This is Melanie Cole, thanks, so much for listening.