Predict before reading
Opening case
A well-appearing term newborn in room air has a right-hand saturation of 97% and a foot saturation of 93%, with reliable waveforms.
Repeat once in 1 hour. The foot value is in the 90% to 94% indeterminate range. The updated algorithm requires both sites to be at least 95% to pass. A common unsafe error is passing the infant because one site is at least 95%.
Learning objectives
- Correctly obtain preductal and postductal oxygen saturations.
- Classify a screen as pass, immediate fail, or indeterminate.
- Use the updated single-retest pathway.
- Evaluate failed screening for both cardiac and noncardiac causes of hypoxemia.
- Avoid false reassurance after a normal screen, especially with possible left-sided obstruction.
Core mental model: pulse oximetry screens for hypoxemia. It does not directly screen cardiac anatomy.
What changed
| Element | Updated approach | Clinical purpose |
|---|---|---|
| Pass threshold | Both right hand and foot must be at least 95%. | Simplifies interpretation and may improve sensitivity. |
| Retesting | One repeat after an indeterminate first screen. | Shortens time to recognition and further evaluation. |
| Respiratory condition | Screen in room air, or on respiratory support delivering FiO2 21%. | Avoid masking hypoxemia with supplemental oxygen. |
Measurement and documentation checklist
Obtain reliable values
- Use the right hand for the preductal value and either foot for the postductal value.
- Confirm a stable, reliable signal and appropriate sensor contact.
- Record each actual saturation separately. Do not average the values.
- Calculate the absolute difference: |right hand - foot|.
- Document respiratory support and effective FiO2.
Do not substitute
- Do not use the left hand as the preductal site.
- Do not pass an infant based on only one value of at least 95%.
- Do not let artifact delay assessment of an ill infant.
- Do not use a passing screen to overrule concerning examination findings.
Scope: The AAP algorithm supplies the interpretation rules. Exact timing, documentation, notification, echocardiography, NICU, and reporting workflows should follow current institutional and state policy.
Table 1. Conditions detected by CCHD pulse-oximetry screening
A failed screen may identify a core CCHD lesion or a clinically important secondary, non-CCHD cause of hypoxemia.
| Category | Conditions |
|---|---|
| Core conditions (CCHD) | Coarctation of the aorta Double outlet right ventricle Ebstein anomaly Hypoplastic left heart syndrome Interrupted aortic arch Pulmonary atresia Single ventricle, not otherwise specified Tetralogy of Fallot Total anomalous pulmonary venous return D-transposition of the great arteries Tricuspid atresia Truncus arteriosus Other critical cyanotic lesions, not otherwise specified |
| Secondary conditions (non-CCHD) | Hemoglobinopathy Hypothermia Infection, including sepsis Lung disease, congenital or acquired Noncritical congenital heart defect Persistent pulmonary hypertension Other hypoxemic condition, not otherwise specified |
Important apparent contradiction: Coarctation is listed as a core target condition, but pulse oximetry may miss coarctation because early hypoxemia can be absent. A target condition is not necessarily a reliably detected condition.
Clinical implication: do not dismiss a failed screen as a false positive simply because echocardiography excludes CCHD. Continue evaluating persistent hypoxemia.
Adapted for resident education from Table 1 of the AAP clinical report, which reprints the conditions from Oster ME, Aucott SW, Glidewell J, et al. Pediatrics. 2016;137(5):e20154573.
Table 2. Recommendations to improve newborn CCHD screening
Bedside now
Thresholds, one retest, room-air screening, limitations, and evaluation of non-CCHD hypoxemia.
Systems and quality
Minimum datasets, program and records linkage, education, and EHR-supported implementation.
The AAP clinical report organizes the recommendations into five implementation areas. This resident-facing rendering preserves the report's recommendation and rationale structure.
| Area | Recommendation | Rationale |
|---|---|---|
| Algorithm | 1. The lower limit of an acceptable oxygen saturation should be ≥95% in both the preductal and postductal measurements. | Less confusion and misinterpretation; potentially increased sensitivity without a clinically significant impact on retesting rates. |
| Algorithm | 2. Use only one retest after an indeterminate result. | Shorter time to recognition of CCHD; potentially increased sensitivity without a clinically significant impact on retesting rates. |
| Clinical condition | 3. The newborn should not be receiving supplemental oxygen during screening. | Avoids false-negative screening. |
| Data collection | 4. Use the recommended minimum dataset. | Improves the ability to monitor and assess the impact of CCHD screening. |
| Data collection | 5. Link newborn screening programs with birth-defects monitoring programs and vital records. | Helps states and territories detect false-negative results and identify opportunities to improve screening. |
| Education | 6. Teach the limitations of screening. | CCHD may still be present after a passing screen. |
| Education | 7. Teach that screening may identify disease other than CCHD. | Supports recognition of other hypoxemic conditions. |
| Education | 8. Expand use of health information technology and optimize electronic health records. | Streamlines implementation and improves compliance. |
Resident application: Table 2 is broader than bedside interpretation. It also addresses surveillance, linkage of programs and records, education, and EHR-supported implementation.
Figure 1 in practice: apply the algorithm
Use the right hand for the preductal measurement and either foot for the postductal measurement. The pathway below is an accessible teaching reconstruction of Figure 1.
Rule precedence: First ask whether either value is below 90%. If yes, the result is an immediate fail regardless of the other value. If no, test the pass criteria. Anything else is indeterminate.
Any saturation <90%
→
Immediate FAIL
Both saturations ≥95%
and absolute difference ≤3%
and absolute difference ≤3%
→
PASS
A saturation 90% to 94%
or absolute difference >3%
or absolute difference >3%
→
Repeat once in 1 hour
Repeat remains indeterminate
→
FAIL
Do not screen on supplemental oxygen. The clinical report specifies no respiratory support or respiratory support with FiO2 21%.
Failed-screen response
A failed screen is not a diagnosis. It is a trigger for prompt clinical evaluation.
Unstable or severely hypoxemic: stabilize and escalate immediately. Do not wait for a routine repeat.
Stable with an indeterminate first screen: repeat once in 1 hour while continuing clinical observation. Do not discharge before resolution.
Stable with an immediate fail or failed repeat: notify the responsible clinician and begin evaluation for CCHD and non-CCHD hypoxemia.
- Assess immediately: appearance, work of breathing, perfusion, pulses, temperature, and complete vital signs.
- Verify the measurement: correct sites, reliable signal, warm extremity, and room-air status.
- Escalate: notify the responsible clinician and evaluate for CCHD. Obtain pediatric cardiology input and echocardiography according to the clinical situation and local protocol.
- Keep the differential broad: consider PPHN, infection including sepsis, pneumonia or other lung disease, hypothermia, hemoglobinopathy, and other hypoxemic conditions.
- Do not stop at a normal cardiac study if hypoxemia persists: continue evaluation for noncardiac causes.
Unstable infant: stabilize and escalate care immediately. Do not delay treatment while completing a screening pathway.
Limitations that matter at the bedside
A pass does not rule out congenital heart disease.
- Pulse oximetry is less effective for lesions that do not produce early hypoxemia.
- Coarctation can be missed. Abnormal femoral pulses, poor perfusion, a blood-pressure concern, feeding difficulty, tachypnea, shock, or metabolic acidosis still require evaluation.
- Prenatal imaging, the newborn examination, family history, and evolving clinical findings remain important.
Interactive resident quiz
Choose one answer for each question. Feedback appears immediately. Your first submitted answer is scored. Questions explicitly test Table 2 and every decision branch in Figure 1.
Score: 0 / 17
Complete answer key with explanations (unlocks after submission)
60-second take-home card
Pass: both right hand and foot ≥95%, with an absolute difference ≤3%.
Immediate fail: any saturation <90%.
Indeterminate: 90% to 94% in either site or difference >3%. Repeat once in 1 hour. Persistent indeterminate result is a fail.
Safety rule: screen in room air. A pass does not exclude CHD, particularly coarctation.
Immediate fail: any saturation <90%.
Indeterminate: 90% to 94% in either site or difference >3%. Repeat once in 1 hour. Persistent indeterminate result is a fail.
Safety rule: screen in room air. A pass does not exclude CHD, particularly coarctation.
Primary source: Oster ME, et al. Newborn Screening for Critical Congenital Heart Disease: A New Algorithm and Other Updated Recommendations. Pediatrics. 2025;155(1):e2024069667. doi:10.1542/peds.2024-069667.