CT just mandated that CF had to be included in it's Newborn Screening program this month (about time!) Our testing looks for about 30 diseases/disorders. The CF screen we do checks the IRT level (Immunoreactive Trypsinogen, a substance produced by the pancreas). It is not a perfect test, but will catch most babies with CF, since their level is usually elevated. If it's high, a 2nd test is done a couple weeks later and then followed up with a sweat test if needed.