Wentworth-Douglass Hospital
(603) 742-5252
Decrease (-) Restore Default Increase (+) font size
Physicians
Site Search

Infant blood sample
Infant blood sample


Definition:

Neonatal cystic fibrosis screening is a blood test that looks for increased levels of immunoreactive trypsinogen (IRT), an enzyme produced by the pancreas. The test is performed on newborns to screen for cystic fibrosis (CF).



Alternative Names:

Cystic fibrosis screening - neonatal; Immunoreactive trypsinogen; IRT test



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.



How to prepare for the test:

There is no special preparation needed.

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.



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.



Normal Values:

Normal values vary from lab to lab. Ask your doctor or testing center for details.



What abnormal results mean:

It is important to remember that a positive screening test for cystic fibrosis does not diagnose cystic fibrosis. If your child's test is positive, further tests will be done to confirm the possibility of CF. Not all children with a positive screening IRT test have CF.



What the risks are:

Risks associated with the test include:

  • Infection (a slight risk any time the skin is broken)
  • Anxiety over false positive tests
  • False reassurance over false negative tests


Special considerations:

The IRT level does not indicate the severity of the CF. False-positives may occur.



References:

Farrell PM, Rosenstein BJ, White TB, et al. Guidelines for diagnosis of cystic fibrosis in newborns through older adults: Cystic fibrosis consensus report. Journal of Pediatrics. Aug 2008;153(2).




Review Date: 2/5/2009
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com


Find What You Need

Events
Careers
Foundation
About Us
Contact
Directions
News
Social Media Agreement
Joint Notice
Web Privacy Policy
WDH Staff Portal

Centers & Services

Cancer Center
Cardiovascular Care
Joint Replacement
Women & Children's
Physician Offices
Other Services

Conditions & Treatments

Health Library

Support Services

Support Groups
Care-Van
Dental Center
Social Work
Food & Nutrition
Integrative Wellness
Spiritual Care
Concerns & Grievances
Homecare and Hospice

For Patients

Pay Your Bill Online
Pricing Estimates
Financial Assistance
Interpreter Services
Surgery Preparation
Medical Record Request
Advance Directives
Clinical Research & Trials

For Healthcare Professionals

Work and Life
Financial Well-Being
Career and Growth

The Wentworth-Douglass Health System includes:

 

Address

Wentworth-Douglass Hospital
789 Central Avenue, Dover, NH 03820
Phone: (603) 742-5252
Toll free: 1 (877) 201-7100