Establishment of reference ranges for prolactin in neonates, infants, children and adolescents.

Prolactin was determined in the sera of 686 healthy neonates, infants, children and adolescents (age range 5 days to 18 years), using the IMx from Abbott Laboratories. The applied test was a microparticle enzyme immunoassay (MEIA). The proband collective was divided into 9 age groups, and each age group into males and females. In accordance with the recommendations of the International Federation of Clinical Chemistry, the 95% scatter range was taken as the reference range. Only a few reference groups showed a normal Gaussian distribution. In addition to the 50th percentile, the 2.5th and 97.5th percentile were calculated for all reference groups, and the minimal and maximal values were also reported. From the age of 12 years onwards, significant differences were found between males and females. The U-test of Mann & Whitney was used to test for significant differences between individual reference groups. Groups showing no significant differences were combined, and the corresponding reference ranges for serum prolactin were then calculated.