Predictive value of umbilical cord blood bilirubin for postnatal hyperbilirubinaemia.
OBJECTIVE
The study investigated the predictive value of umbilical cord serum (UCS) bilirubin for the postnatal course of bilirubinaemia in healthy term and near-term newborns.


METHODS
Term appropriate-for-gestational-age (AGA; n=1100), small-for-gestational-age (SGA; n=163) and near-term infants (GA 34-36 wk; n=78) were included and separated according to their UCS bilirubin levels, starting from <20 (group 1), 20-<30 (2), 30-40 (3) and >40 (4) micromol/l. The newborns were followed for at least 5 postnatal days, and UCS bilirubin values were correlated with the development of hyperbilirubinaemia and phototherapy (PT) treatment.


RESULTS
A clear relation between UCS bilirubin and the development of hyperbilirubinaemia was found in all three patient populations. None of the 75 AGA patients of group 1 developed postnatal bilirubin values above 300 micromol/l, whereas 0.3, 3.4 and 8.6% of the patients in groups 2-4, respectively, did so. The frequency of PT increased from 0% in group 1 up to 9.6% in group 4. For the prediction of further need of PT using a UCS bilirubin cut-off level of 30 micromol/l, we found a sensitivity of 90% and a negative predictive value of 99.1%, indicating that all patients with UCS bilirubin values below 30 micromol/l (443/1100 or 40.2%) were at a very low risk of developing dangerous hyperbilirubinaemia. Similar results were obtained in SGA children with a sensitivity of 94.1% and a negative predictive value of 98.6%. In comparison to term newborns, we generally found higher bilirubin values in preterms. A total of 6.4% of preterm children developed bilirubin values over 300 micromol/l, compared with 3% of term children, and 47.4% of preterms had to be treated with PT. Predicting the need of PT by using a UCS bilirubin cut-off level of 30 micromol/l revealed a sensitivity of 70.3% and a negative predictive value of 65.6%.


CONCLUSIONS
These data suggest that UCS bilirubin is useful in predicting the postnatal bilirubin values in term and near-term newborns. We presume that the use of UCS bilirubin values may help detect infants at low risk for postnatal hyperbilirubinaemia and minimize an unnecessary prolongation of hospitalization.
Knüpfer
Matthias
M
Children's Hospital, Department of Neonatology, University Hospital, Leipzig, Germany. knuem@medizin.uni-leipzig.de
Pulzer
Ferdinand
F
Gebauer
Corinna
C
Robel-Tillig
Eva
E
Vogtmann
Christoph
C
D001663:Bilirubin / Q000097:blood*; D001724:Birth Weight; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000175:diagnosis* / Q000628:therapy; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D010789:Phototherapy; D011237:Predictive Value of Tests
D001663:Bilirubin