7.2 Universal Screenings: CCHD, Universal Hearing Screen & Metabolic Bloodspots

7.2 Universal Newborn Screening

Core Focus: Screening identifies apparently well infants who need diagnostic evaluation. A symptomatic newborn bypasses the screening pathway and receives clinical assessment immediately.

Critical congenital heart disease pulse oximetry

Screen at 24 hours or later, or as late as possible before an earlier discharge. Measure preductal saturation on the right hand and postductal saturation on one foot using motion-tolerant equipment and a reliable waveform. Do not use the left hand as the standard preductal site.

The 2025 AAP algorithm is:

• Pass: both right-hand and foot saturations are >=95% and the absolute difference is <=3 percentage points.
• Immediate fail: either reading is <90%. Notify the clinician and evaluate without repeating merely to obtain a better number.
• Indeterminate: either reading is 90%–94% or the difference is >3 points. Repeat both sites once in one hour.
• Fail after repeat: the repeat does not meet all pass criteria.

This updated algorithm has one repeat, not the older sequence of two repeat attempts. A failed screen does not diagnose one lesion; evaluation considers exam, blood pressure/pulses, respiratory disease, infection, hemoglobin, and often echocardiography. A pass does not exclude every cardiac defect, especially coarctation. Weak femoral pulses, shock, cyanosis, or respiratory distress requires evaluation even after a pass.

Hearing screening

Complete screening before one month of age, preferably before discharge, using the program's protocol:

• Otoacoustic emissions (OAE) assess sound generated by functioning cochlear outer hair cells. Vernix, fluid, debris, or noise can cause a non-pass.
• Automated auditory brainstem response (AABR) assesses neural transmission from the cochlea through the brainstem and can detect auditory neuropathy missed by OAE.

Screen both ears. A non-pass is not a diagnosis, and repeated bedside attempts must not delay diagnostic follow-up. Arrange rescreening and audiologic diagnosis under the current Early Hearing Detection and Intervention pathway, with intervention promptly when loss is confirmed. Infants with risk factors such as congenital CMV, craniofacial anomaly, meningitis, or prolonged NICU care need surveillance even after passing.

Dried bloodspot screening

State and territorial programs determine the panel, collection window, repeat rules, and urgent follow-up. Many collect after 24 hours, but an early discharge specimen is still obtained when required and repeated on the program's schedule. Do not claim that every infant must consume protein for exactly 24 hours or that one universal repeat interval applies nationwide.

Warm the heel if needed, identify the safe medial or lateral plantar surface, allow antiseptic to dry, use the approved lancet depth, and let a free-flowing drop saturate each printed circle from one side. Do not layer drops, squeeze excessively, touch the filter paper, or heat the card. Air-dry flat and submit promptly with complete demographics, feeding/transfusion information, collection time, and birth time.

Blood transfusion, parenteral nutrition, prematurity, early collection, and some medications can change interpretation and repeat requirements. An out-of-range screen is not a diagnosis, but some results are time-critical. Confirm receipt, contact the family promptly, and arrange the exact confirmatory tests and specialty treatment ordered by the screening program.

Follow-up is part of screening

Before discharge, verify the primary care appointment, working contact information, pending-test responsibility, and interpreter needs. Document who will track each result. Screening fails its purpose if a repeat or diagnostic referral is not completed.

Special situations and communication

Do not perform routine CCHD screening while an infant is receiving supplemental oxygen simply to produce a “passing” value; follow the protocol for oxygen-dependent/NICU infants and investigate the underlying need. Confirm signal quality, probe placement, warm perfusion, and a calm extremity before accepting a saturation. If a screen fails, keep the family informed that noncardiac conditions—such as pulmonary disease, infection, or persistent pulmonary hypertension—can also produce hypoxemia and also require evaluation.

For hearing screening, document each ear and the technology used. Explain “pass” and “did not pass” rather than “normal” and “deaf.” A non-pass can reflect transient debris, but it must not be dismissed. Congenital CMV testing has a limited window for proving congenital rather than postnatal infection, so follow the jurisdiction's targeted CMV pathway promptly when hearing screening triggers it.

Metabolic screens can reveal emergencies before obvious symptoms. Poor feeding, vomiting, lethargy, tachypnea, unusual odor, hypoglycemia, acidosis, or hyperammonemia requires immediate clinical evaluation even when the screen is pending or previously reported normal. Newborn screening never replaces diagnostic judgment.