Pulse Oximetry Screening in Newborns
The short answer
Pulse oximetry screening (measuring blood oxygen levels) is done on all newborns before hospital discharge to screen for critical congenital heart disease (CCHD). A normal result is reassuring but does not rule out all heart defects. An abnormal result requires further evaluation but does not necessarily mean there is a problem. Most babies with abnormal results have normal hearts.
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By Age
What to expect by age
Pulse oximetry screening is performed at 24-48 hours of age by placing a sensor on the baby's right hand and one foot. Normal oxygen saturation is 95% or above with less than a 3% difference between the two sites. A failed screen (oxygen below 95% or a difference above 3%) may indicate a CCHD that reduces oxygen levels. However, false positives occur, and an abnormal screen does not confirm heart disease. Follow-up includes repeat screening, echocardiography, and clinical evaluation. If a CCHD is confirmed, early treatment significantly improves outcomes.
If the pulse ox screen was normal and baby is doing well, no further testing is needed. If a heart defect was identified, the pediatric cardiologist will manage ongoing care. Some heart defects present after discharge, so continue to watch for signs like blue/gray skin, rapid breathing, and poor feeding.
Continued monitoring if a heart defect was identified. Normal screening does not rule out all heart conditions, so report any new symptoms to your pediatrician.
Ongoing follow-up for any identified cardiac condition. Normal screening in the newborn period is reassuring.
What Should You Do?
When to take action
- Oxygen saturation 95% or above in both right hand and foot with less than 3% difference
- Baby is pink, feeding well, and breathing comfortably
- Screening passed on first attempt
- You have questions about what the screening means or your baby's results
- Family history of congenital heart disease
- You notice any color changes in your baby after going home
- Failed pulse ox screening requires immediate follow-up evaluation
- Baby appears blue or gray, has rapid or labored breathing, or is feeding poorly after discharge
Sources
Related Resources
Trust your instincts. If something feels wrong, reach out to your pediatrician.
Worrying about your baby means you care. That is a good thing.
Related Medical Concerns
Congenital Heart Defect Signs in Babies
Congenital heart defects (CHDs) are the most common type of birth defect, affecting about 1 in 100 babies. They range from small holes in the heart that may close on their own to complex defects requiring multiple surgeries. Early detection through pulse oximetry screening and recognizing key signs — such as blue skin, rapid breathing, poor feeding, and failure to gain weight — is critical. Advances in surgery have dramatically improved survival and quality of life.
Heart Murmur Detected at Birth
Heart murmurs are very common in newborns and are often innocent (harmless). They are extra sounds heard with a stethoscope caused by blood flowing through the heart. Many murmurs detected at birth resolve on their own as the circulatory system transitions from fetal to newborn circulation. Your pediatrician may order an echocardiogram to confirm the murmur is innocent.
My Baby Turns Blue (Cyanosis)
Blue or purple discoloration limited to a baby's hands and feet (acrocyanosis) is very common in newborns and usually harmless, caused by immature circulation. However, blue coloring of the lips, tongue, face, or trunk (central cyanosis) is always a medical emergency that requires immediate evaluation, as it may indicate a heart or lung problem.
My Baby's Head Shape Looks Abnormal
Many babies develop temporary head shape irregularities that are completely normal. A cone-shaped head from vaginal delivery reshapes within days. Mild positional flattening (plagiocephaly) from sleeping on the back is very common and usually improves with repositioning and tummy time. However, head shape changes involving ridges, a persistently bulging fontanelle, or rapid head growth changes should be evaluated to rule out craniosynostosis.
Achondroplasia (Dwarfism) in Babies
Achondroplasia is the most common form of short-limbed dwarfism, affecting about 1 in 15,000 to 40,000 births. It is caused by a mutation in the FGFR3 gene and is usually apparent at birth with characteristic features including short limbs, a larger head, and a prominent forehead. Intelligence is normal. With monitoring for specific complications and supportive care, children with achondroplasia lead full, active, and independent lives.
Adenoid Hypertrophy and Breathing
Adenoids are lymphoid tissue located behind the nose that help fight infection in young children. When adenoids become enlarged (adenoid hypertrophy), they can block the nasal airway, causing chronic mouth breathing, snoring, nasal speech, and sleep-disordered breathing. Enlarged adenoids are most common between ages 2-7 and are a leading cause of obstructive sleep apnea in young children. Treatment ranges from watchful waiting and nasal steroids to surgical removal (adenoidectomy) if breathing or sleep is significantly affected.