Cystic fibrosis-related deaths in infancy and the effect of newborn screening

Although newborn screening for cystic fibrosis (CF) is widely advocated, ha rd evidence in its favor is difficult to obtain, partly because of a dramat ically improved life expectancy. Between 1985-1989 infants, born in Wales a nd the West Midlands were randomized to newborn CF screening by heel-prick immunoreactive trypsin (IRT) measurement or diagnosis by clinical presentat ion. Eligible children with CF who died in the first 5 years of life were i dentified from the local pediatricians and from the National UK CF Survey. In all, 230,076 infants were randomized to be screened, while 234,510 were unscreened. One hundred seventy-six CF children were identified, of whom 7 died in the first 5 years of life, 3 having presented with meconium ileus. Median age of diagnosis in the screened group was 8 weeks. On an intention to treat analysis, all 4 nonmeconium ileus-related deaths occurred in the u nscreened group (Fisher's exact test, P < 0.05). However, the clinical pres entation of 2 of these infants led to them being diagnosed prior to 8 weeks , i.e., earlier than would have been likely by screening, In conclusion, newborn screening has the potential to decrease infant CF de aths, but if it is to be successful, identification and treatment must occu r as soon as possible after birth. (C) 2001 Wiley-Liss. Inc.