Key takeaways: Newborn blood screening checks for dozens of rare but treatable conditions. A hearing screen checks for hearing loss. An abnormal or “refer” result means more testing is needed, not that your baby definitely has a condition. Follow up quickly.
Every baby in the U.S. is offered newborn screening before leaving the hospital. If you get a call that your baby needs a repeat test, it’s natural to worry. Here’s what these tests are and what results mean.
Newborn Blood Screening (Heel Stick)
What it is: a few drops of blood from your baby’s heel, collected on special filter paper, usually 24 to 48 hours after birth.
What it checks for: dozens of rare conditions that may not cause symptoms at first but can be treated if found early. These include:
- Metabolic disorders, like phenylketonuria (PKU).
- Endocrine disorders, like congenital hypothyroidism.
- Blood disorders, like sickle cell disease.
- Cystic fibrosis.
- Spinal muscular atrophy and severe combined immunodeficiency (SCID).
Each state decides which conditions to screen for, guided by the federal Recommended Uniform Screening Panel.
Why timing matters: some tests are more accurate after 24 hours of age and feeding. Babies discharged before 24 hours may need a repeat test.
What an Abnormal Result Means
An out-of-range result means your baby needs more testing. It doesn’t mean your baby has the condition. Many abnormal screens are “false positives,” caused by:
- Testing too early.
- Prematurity or illness.
- Blood transfusions.
- Sample handling issues.
Your pediatrician or the state program will tell you what follow-up is needed, sometimes a repeat heel stick, sometimes specific blood tests or a specialist visit. Some conditions need prompt action, so follow up right away.
Some states also routinely repeat newborn screening at 1 to 2 weeks.
From the author
From First Breath to First Birthday is my month-by-month guide to your baby’s first year, written as a NICU and postpartum nurse. My book starts in the first hours after birth and walks you through every newborn check and the weeks that follow.
Newborn Hearing Screening
What it is: a quick, painless test, often done while your baby sleeps.
- OAE (otoacoustic emissions): a small earphone measures echoes from the inner ear.
- AABR (automated auditory brainstem response): sensors on the head measure brain responses to sounds.
Why it matters: about 1 to 3 of every 1,000 babies are born with permanent hearing loss. Early identification supports language development.
What a “Refer” Result Means
“Refer” means your baby didn’t pass and needs a follow-up test. It doesn’t mean your baby has hearing loss. Common reasons include:
- Fluid or debris in the ear canal after birth.
- Movement or crying during the test.
- Background noise.
Most babies who are referred pass the rescreen.
The 1-3-6 Goals
National hearing guidelines aim for:
- Screening by 1 month.
- Diagnosis by 3 months for babies who don’t pass.
- Intervention by 6 months for babies with hearing loss.
Some states are moving toward even earlier goals.
Hearing Can Change
Passing the newborn screen doesn’t rule out later hearing loss. Watch for hearing milestones, like startling at loud sounds, turning toward voices, and babbling. Tell your doctor if you have concerns at any age.
Critical Congenital Heart Disease (CCHD) Screening
Pulse oximetry screening, done after 24 hours, checks oxygen levels to find some serious heart defects. A failed screen leads to further evaluation, usually an echocardiogram.
Call your baby’s doctor promptly if: you’re told a screening result is abnormal and you haven’t been contacted about next steps; your baby is feeding poorly, very sleepy, vomiting, or has trouble breathing.
The Bottom Line
Newborn screening catches rare but serious conditions early. An abnormal or “refer” result means more testing is needed, not a diagnosis. Follow up quickly.
Want more support for your baby’s first year? My book, From First Breath to First Birthday, is available on Amazon.
Related Articles
- Your Newborn’s First 24 Hours: What Happens in the Hospital, Hour by Hour
- Newborn Hearing: What Babies Hear and How to Protect Their Ears
Sources
- Health Resources and Services Administration, Advisory Committee on Heritable Disorders in Newborns and Children. Recommended Uniform Screening Panel. https://www.hrsa.gov/advisory-committees/heritable-disorders/rusp
- Joint Committee on Infant Hearing. Year 2019 position statement: principles and guidelines for early hearing detection and intervention programs. J Early Hear Detect Interv. 2019;4(2):1-44.
- Centers for Disease Control and Prevention. Newborn screening; Hearing loss in children. https://www.cdc.gov
- Martin GR, Ewer AK, Gaviglio A, et al. Updated strategies for pulse oximetry screening for critical congenital heart disease. Pediatrics. 2020;146(1):e20191650.
- Baby’s First Test. https://www.babysfirsttest.org
This article is for general education and is not a substitute for individualized medical advice. Always talk with your baby’s health care provider or your own provider about your specific situation. If you think your baby or you may have a medical emergency, call 911.
