Diagnostic Accuracy of Umbilical Cord Bilirubin Measurement in Development of Significant Hyperbilirubinemia in Healthy Neonates
Background: To determine the diagnostic accuracy
of umbilical cord blood bilirubin in determining the
development of significant hyperbilirubinemia on
the 3rd day of life in healthy full term newborns,
keeping serum bilirubin as a gold standard.
Methods: In this cross sectional study babies
delivered consecutively were taken.Any condition
which can aggravate hyperbilirubinemia and any
patient with congenital abnormality were excluded.
Cord blood sample was collected from the neonatal
end of the umbilical cord after it had been cut and
investigated for serum total bilirubin (STB).
Venous sample was taken on the 3rd day of life and
sent for serum total bilirubin. Babies were then
discharged or admitted for treatment depending on
their serum total bilirubin levels. Mean serum total
bilirubin in cord blood and mean total serum
bilirubin on 3rd day of life was calculated. A 2 x 2
table was constructed to determine sensitivity,
specificity positive and negative predictive values.
Results: The mean cord STB was 2.0 mg/dl ± 0.6.
Out of the 115 babies, 26% developed significant
hyperbilirubinemia requiring phototherapy, only
one needed exchange transfusion. The results
showed that cord blood bilirubin ≥2.5mg/dl had the
high sensitivity (87%) and specificity (98%) to
predict the newborn that would develop significant
hyperbilirubinemia. At this level the negative
predictive value was 95%. The diagnostic accuracy of
cord bilirubin 94.8%.
Conclusion: A cord blood STB of ≥2.5md/dl is
predictive of significant hyperbilirubinemia on the
3rd day of life in healthy neonates