Cystic fibrosis is one of the most common genetic disorders, occurring in approximately 3,500 live births. Many parents of children with cystic fibrosis are unaware that they are carriers for the disorder. Carriers show no symptoms of cystic fibrosis but they can pass the condition on to their offspring. Therefore, many people who are carriers do not have routine cystic fibrosis genetic testing, even though it is available. This means that newborn genetic screening is very important. Most places in North America have universal newborn genetic testing for a variety of genetic disorders, including cystic fibrosis [source: March of Dimes].
Typically, a nurse will take a very small sample of your newborn's blood soon after birth, while you are both still in the hospital. The blood sample is then sent to a lab to test for signs of cystic fibrosis. The initial screening test measures the level of a chemical called immunoreactive trypsinogen (IRT) that the pancreas produces. High levels of IRT are a sign of cystic fibrosis, as well as other health-related issues, such as a stressful delivery or premature birth. Therefore, a positive test is only one indication that further testing is required, and it does not necessarily mean your infant has cystic fibrosis. Follow-up testing typically involves a more comprehensive genetic test or a sweat test. A sweat test involves testing the level of salt in your newborn's sweat.
Early identification of cystic fibrosis is essential for a child's health and lifespan. Children who receive a diagnosis of cystic fibrosis early in life have better nutrition and fewer health complications compared to children who are not identified early [source: Cystic Fibrosis Foundation]. Infants who receive newborn screening are typically diagnosed with cystic fibrosis within the first two months of life [source: March of Dimes].