46 Delay in meconium emission: should it be considered a risk for cystic fibrosis?

Abstract

Background: Ten to 15% of CF infants present with meconium ileus (MI), that sometimes can lead to intestinal malformation. Serum immunoreactive trypsin (IRT) levels may be normal and newborn screening (NBS) could be erroneously considered negative. In our CFNBS protocol newborn babies presenting problems with meconium passage (delay in meconium emission − MD − included) undergo sweat test also if IRT is negative Aim: The aim of this study is to investigate the incidence of CF in neonates with MI and MD to determine if infants with this last condition have to be submitted to CF diagnostic test. Patients and Method: A retrospective 5-year study examines neonates screened in our Center that presented problems in meconium passage, with regard to IRT values and CF diagnosis. Results: In a 5-year period (2006–2010) we screened 172,185 newborns and diagnosed 50 CF. Eigthy-two newborns were reported having some problems related to meconium passage: 13 were referred as MI (group 1), 7 as intestinal atresia (IA) (group 2), 62 as MD (group 3). In group 1 8/13 had IRT positive, 6/13 were diagnosed as CF and one of them had IRT normal value; 2 died without diagnosis. In group 2 6/7 had IRT negative, 2/7 had CF and one of them was IRT negative. In group 3 nobody out 62 had IRT positive, nor positive sweat test. Conclusion: In this series 12% of CF neonates presented with MI and/or IA, and 2 of them were IRT negative confirming that CF with MI and IA can have negative NBS. Delay in meconium pass is therefore, asscociated neither with positive screening nor with CF, suggesting that newborns with MD and IRT negative don’t require further analysis for CF.