[Concentration of bilirubin in the umbilical blood as an indicator of hyperbilirubinemia in newborns].

UNLABELLED: The aim of this study was to estimate the correlation between concentration of bilirubin in the umbilical blood and occurrence of icterus in newborns.

MATERIAL AND METHOD: The study investigations covered 187 healthy, full-term newborns in good general condition. Newborns with serological incompatibility were not included into the study. In 155 (83%) cases babies were born through natural passages, in 32 (17%) by Caesarean section. The umbilical blood was taken immediately after delivery and the venous blood on the 3rd day of life to determine concentration of bilirubin. The concentration of bilirubin was determined by spectrophotometry. Bilirubin values lower than 12.9 mg% were considered physiological. Hyperbilirubinemia was recognized when the concentration of bilirubin was over 12.9 mg%. Pearson test was used to estimate the correlation between bilirubin value in the umbilical blood and the venous blood. In case when the value of correlation coefficient was statistically significant the linear regression equation was determined.

RESULTS: The mean value of total bilirubin in the umbilical blood was 1.30 mg% +/- 0.47 and in venous blood on the 3rd day of life 8.07 mg% +/- 3.08. The value of concentration coefficient between concentration of total bilirubin, unconjugated and conjugated bilirubin was adequately 0.49 (p < 0.001), 0.31 (p<0.005) and 0.5 (p<0.001). No one with umbilical bilirubin concentration lower than 1 mg% developed hyperbilirubinemia.

CONCLUSION: The concentration of bilirubin in the umbilical blood can be useful indicator of risk of icterus in newborns. The special care is need for newborns whose concentration of bilirubin in umbilical blood is over 1 mg%.