Definition of Neonatal cystic fibrosis screening:

Neonatal cystic fibrosis screening is a blood test that screens newborns for cystic fibrosis (CF). Cystic fibrosis is disease passed down through families that causes thick, sticky mucus to build up in the lungs and digestive tract. It can lead to breathing and digestive problems.

How the test is performed:

A sample of blood is either taken from the bottom of the baby's foot of a vein in the arm. A tiny drop of blood is collected onto a piece of filter paper and allowed to dry. The dried blood sample is sent to a lab for analysis.

The blood sample is examined for increased levels of immunoreactive trypsinogen (IRT), a protein produced by the pancreas that is linked to CF.

How the test will feel:

The brief feeling of discomfort will probably cause your baby to cry.

Why the test is performed:

Children with CF who are diagnosed early in life and start treatment at a young age may have better nutrition, growth, and lung function. Newborn screening tests allow doctors to identify children with CF before they have symptoms.

Some states include this test in the routine newborn screening tests that are done before the baby leaves the hospital.

If you live in a state that does not perform routine CF screening, your health care provider will explain whether testing is needed.