For immediate clinical concerns page the on call Pediatric Cardiologist at 1-608-262-2122, and for technical assistance Monday through Friday during business hours email us at

POX Screening Decision Tool

Information for Families

Información en Español

Information for Families Handout

Congratulations on the birth of your baby! Becoming a new parent is a wonderful and challenging time filled with unexpected joys and uncertainties.

After your baby is born, your health care team will do some exams and tests. One test is for serious heart problems that your baby may have at birth. Health care providers call these problems “Critical Congenital Heart Disease (CCHD).“  

This test for serious heart problems is called pulse oximetry. This test:

  • measures oxygen in your baby’s blood.
  • is easy and painless.
  • is usually done when your baby is between 24 to 48 hours old. (If your child is on supplemental oxygen in the first days after birth, the pulse oximetry testing may be postponed.)

To do this test, your nurse will put a small sticker, called a probe, on your baby’s right hand and on your baby’s foot. The probe measures the oxygen in your baby’s blood.

Most babies will pass this screening test the first time and will not need any more tests. A small number of babies will need to have the pulse oximetry screening repeated. Babies with very low oxygen levels or moderately low oxygen levels on repeated testing will usually need to have another test called an echocardiogram to determine if they have an important heart problem.

An echocardiogram is an ultrasound test of your baby’s heart. An echocardiogram is painless and is like the ultrasound some mothers have when they are pregnant. Many hospitals can perform an echocardiogram for babies, but some babies may need to go to a different health care facility to have an echocardiogram.

It is important to remember that pulse oximetry screening will not identify babies who have problems with their hearts but who have normal oxygen levels.

The reason to do pulse oximetry screening is to find and treat babies with serious heart problems that are not found during prenatal care or newborn care. For more information, please go to other links on this website.