Clinical Screening and Diagnosis for Critical Congenital Heart Defects

Importance of screening

Newborn screening may identify critical congenital heart defects (CCHDs) before signs are evident. Identifying newborns with these conditions before hospital discharge can help ensure they receive prompt care and treatment. Timely care may prevent disability or death early in life.

Screening guidelines

Current recommendations focus on screening newborns in:

• Well-baby nurseries
• Intermediate care nurseries
• Units where hospital discharge is common during a newborn's 1^st week

Screening is done when a baby is at least 24 hours of age. Or, it is completed as late as possible if the baby is to be discharged before 24 hours of age. Timing the screening around the time of the newborn hearing screening can help improve efficiency. A pulse oximeter is used to measure the percentage of hemoglobin in the blood that is saturated with oxygen.

The following algorithm has been developed to show the steps in screening (Kemper et al., 2011)

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Pulse oximetry screening should not replace taking a complete family health history, pregnancy history, or physical examination. These exams may detect CCHDs before the development of low oxygen levels (hypoxemia) in the blood. Screening with pulse oximetry identifies several types of CCHDs, the most common are below.

Screening targets

Screening with pulse oximetry can identify a number of types of critical CHDs, the most common of which are shown below. While not the main targets of screening, many conditions other than critical CHD may present with hypoxemia. As a result, such conditions may also be detected via pulse oximetry.

Critical CHDs

• Coarctation of the aorta and Hypoplastic left heart syndrome
• Double outlet right ventricle, Ebstein anomaly, and Single ventricle
• Interrupted aortic arch and Tetralogy of Fallot
• Pulmonary atresia and Total anomalous pulmonary venous return
• d-Transposition of the great arteries
• Tricuspid artresia and Truncus ateriosus
• Other CCHDs requiring treatment in the first year of life

Other conditions that are not CCHDs

• Hemoglobinopathy
• Hypothermia
• Infection, including sepsis
• Lung disease (congenital or acquired)
• Non-critical congenital heart defect
• Persistent pulmonary hypertension
• Other hypoxic conditions not otherwise specified

Screening outcomes

Failed screens

A screen is considered failed if at least one of these occur:

1. Any oxygen (O₂) saturation measure is <90% (initial screen/repeat screens)
2. O₂ saturation is <95% in the right hand and foot on 3 measures*
3. A >3% difference in O₂ saturation in the right hand and foot on 3 measures*

*Each separated by one hour

Any infant who fails the screen should have an evaluation for causes of hypoxemia. In most cases this will include an echocardiogram. If a reversible cause of hypoxemia is identified and appropriately treated, an echocardiogram may not be necessary. The infant's pediatrician should be notified immediately and the infant might need to be seen by a cardiologist.

Passed screens

A screen is considered passed when there is an oxygen saturation measure that is:

1. ≥95% in the right hand or foot
2. ≤3% absolute difference between the right hand or foot

When the above conditions are met, screening would end. Pulse oximetry screening does not detect all critical CHDs. Therefore, it is possible for a baby with a passing screening result to still have a critical CHD or other CHD.

Ways to reduce false positive screens

• Screen the newborn while he or she is alert.
• Screen the newborn when he or she is at least 24 hours old.

Resources

Online resources

American Academy of Pediatrics: Critical Congenital Heart Defect (CCHD) Screening Resource for Primary Care Providers. This online resource helps primary care providers navigate the implementation process and provide effective, long-term medical homes for babies with CCHDs.

Children's National Medical Center's Congenital Heart Disease Screening Program has created videos about critical CHD screening for parents and healthcare professionals.

Congenital Heart Public Health Consortium (CHPHC). CHPHC's website provides resources for families and providers on heart defects and screening.

NewSTEPS. This webpage on CCHDs provides a central location for resources related to these conditions, including webinars, legislative updates, and news.

Publications

American Academy of Pediatrics: Endorsement of Health and Human Services Recommendation for Pulse Oximetry Screening for Critical Congenital Heart Disease

Strategies for implementing screening for critical congenital heart disease.

Evidence review: Critical congenital cyanotic heart disease

Role of pulse oximetry in examining newborns for congenital heart disease: A scientific statement from the AHA and AAP

NIH/NLM Newborn Screening Coding and Terminology Guide.

Pulse oximetry screening for critical congenital heart defects in asymptomatic newborn babies: a systematic review and meta-analysis.