Critical CHD Newborn Screening¶

Learning Objectives¶

Core Knowledge & Clinical Reasoning¶

[ ] Apply the updated 2025 CCHD screening algorithm including pass/fail criteria (≥95% or ≤3% difference)
[ ] Identify the 7 primary target lesions detected by pulse oximetry screening
[ ] Recognize limitations of screening (lesions missed: coarctation, TGA with large PDA, TAPVR)
[ ] Evaluate failed screen to differentiate cardiac from pulmonary causes

Clinical Application¶

[ ] Formulate appropriate response to failed CCHD screen (repeat vs echo vs urgent cardiology)
[ ] Interpret screening results in context of clinical exam and other findings

Communication & Counseling¶

[ ] Counsel families on meaning of positive screen (most are false positives)
[ ] Explain next steps and need for echocardiography without causing excessive alarm

Systems-Based Practice¶

[ ] Ensure proper screening technique (timing >24 hours, correct probe placement)
[ ] Coordinate expedited cardiology evaluation for failed screens

Key Guidelines¶

2025 AAP Clinical Report: Newborn Screening for Critical CHD - Updated Algorithm Pediatrics. 2025;155:e2024069667

Quick Reference: CCHD Screening Algorithm

2025 Key Updates¶

Feature	Previous (2011)	Updated (2025)
Passing threshold	≥95% either extremity	≥95% in BOTH extremities
Retests allowed	2 retests	1 retest only
Algorithm	More complex	Simplified

Target Lesions (7 Primary)¶

Ductal-dependent or cyanotic lesions: 1. Hypoplastic left heart syndrome (HLHS) 2. Pulmonary atresia (with intact septum) 3. Tetralogy of Fallot 4. Total anomalous pulmonary venous return (TAPVR) 5. Transposition of great arteries (TGA) 6. Tricuspid atresia 7. Truncus arteriosus

Secondary Detectable Conditions¶

Condition	Notes
Coarctation of aorta	Challenging to detect
Ebstein anomaly	Variable presentation
Critical aortic stenosis
Critical pulmonary stenosis
Interrupted aortic arch
DORV	Double outlet right ventricle
Single ventricle variants

Screening Algorithm (2025)¶

Timing¶

After 24 hours of life (or before discharge if <24 hrs)
Optimally in well-baby nursery

Measurement¶

Pulse oximetry on RIGHT HAND (pre-ductal)
Pulse oximetry on EITHER FOOT (post-ductal)

Pass Criteria¶

PASS if BOTH: - SpO2 ≥95% in pre-ductal (right hand), AND - SpO2 ≥95% in post-ductal (foot) - AND difference ≤3%

Fail Criteria (Immediate Echo)¶

SpO2 <90% in ANY measurement

Repeat Criteria¶

SpO2 90-94% in either location, OR
3% difference between pre- and post-ductal
Only 1 retest allowed (previously 2)
Repeat in 1 hour

After Retest¶

If still 90-94% or >3% difference → FAIL → Echo
If ≥95% both locations and ≤3% difference → PASS

Limitations¶

Sensitivity¶

Overall: 50-76%
Cannot rule out CCHD with negative screen
Coarctation particularly challenging

False Positives¶

Transition period physiology
Pulmonary disease (pneumonia, TTN, meconium aspiration)
PPHN
Sepsis
Hemoglobin variants affecting oximetry

What Screening DOESN'T Detect Well¶

Left-sided obstructive lesions (CoA, AS)
Defects with adequate oxygenation (VSD, ASD)
Lesions that worsen over time

Non-Cardiac Conditions Detected¶

Screening may identify: - Sepsis - Pneumonia/respiratory disease - PPHN - Congenital diaphragmatic hernia - Hemoglobinopathies (rarely)

High-Altitude Considerations¶

False positive rates higher at altitude
May need altitude-adjusted thresholds
Some centers use 93% threshold

Board Pearls¶

Pearl: PASS = SpO2 ≥95% in BOTH pre- and post-ductal

Updated 2025 criteria; difference must be ≤3%

Pearl: Only 1 retest allowed in 2025 algorithm

Previously allowed 2 retests

Pearl: Sensitivity 50-76% - cannot rule out CCHD

CoA particularly difficult to detect

Self-Assessment¶

Q1: A newborn at 28 hours of life has pulse oximetry: right hand 96%, right foot 92%. What is the next step?

Answer

**Answer**: Repeat screen in 1 hour (one retest allowed) **Rationale**: The right hand (pre-ductal) is ≥95%, but the foot (post-ductal) is 92% (between 90-94%). The difference is 4% (>3%). Per 2025 algorithm, this requires one retest in 1 hour.

Q2: A newborn passes CCHD screening at 26 hours of life. At 4 days of life, a murmur is heard and the infant appears pale with weak femoral pulses. What is the most likely diagnosis?