A pancreatic test evaluating immunoreactive trypsinogen that is performed on newborn infants. The test helps to identify who may have cystic fibrosis (CF).

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood is collected onto a test strip. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

Your health care provider will explain the test to you and that false positives and false negatives are possible. You must sign a consent form before the test.

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. The brief feeling of discomfort will probably cause your baby to cry.

Cystic fibrosis is a genetic disease that affects the sweat glands as well as the respiratory and gastrointestinal systems. Trypsinogen is produced by the pancreas and is elevated in babies with cystic fibrosis. This test is a screening tool to identify those infants that need further testing to confirm the diagnosis.

The predicted value of a normal or negative test is an immunoreactive trypsinogen value less than 140 ng/dl.

Note: ng/dl = nanograms per deciliter

Abnormal results, and the strength of the test in predicting CF, is based on where your child's test results fall in relation to the values of all tested children to date and if the test is positive on repeat examination.

If your child's level of immunoreactive trypsinogen is greater than 140 ng/dl on the first screen, the test result is considered positive. If your child's level is 120 ng/dl on the second screen, the second test result is also considered positive.

While these two test results indicate CF may exist, a sweat test with a positive result confirms the diagnosis.

Note: ng/dl = nanograms per deciliter

• excessive bleeding
• fainting or feeling lightheaded
• hematoma (blood accumulating under the skin)
• infection (a slight risk any time the skin is broken)