Effect of gestational length on albumin content of meconium.

During a screening programme for the detection of CF using the meconium albumin technique, the overall false-positive rate was found to be approximately 1%. When the gestational age of the infants was taken into account the false-positive rate was found to be significantly higher in preterm (8%) as compared to term infants (0.55%). This was due largely but not solely to the presence of occult blood. Possible explanations for these findings are discussed and attention drawn to the limitation of meconium albumin content as a screening technique for CF in preterm infants.