Predictive Value Of Cord Blood Bilirubins And Hemolysis Three Test For ABO-hemolytic Disease Of The Newborn And Hyperbilirubinemia

Objective:To investigate the predictive value of cord bolood bilirubins levels and hemolysis three test for ABO-hemolytic disease of the newborn（ABO-HDN）and hyperbilirubinemia by analyzing of umbilical cord blood bilirubins.Methods:193 healthy term newborns who had type-O blood mothers were selected.We detected all of their cord blood bilirubin（CBB） and hemolysis three test.The transcutaneous bilirubin（TCB） was measured daily since their birth and monitored actively. When the infants’ TCB≥100μmol/L within the first 24 h after birth;≥150μmol/L at 48h;≥200μmol/L at 72h;≥250μmol/L at or after 72 h, the venous total serum bilirnbin（TSB） was detected. We divided these infants into five groups according to the level of CBB-starting from 0μmol/L^{group 1}, ≥34.2μmol/L^group2, ≥42.8μmol/L^group3, ≥51.3μmol/L^{group 4}, ≥59.9μmol/L^{group 5}, and compared the ratio of ABO-HDN and hyperbilirubinemia with phototherapy.The receiver operating characteristic（ROC） curve was established,and the results were statistically analyzed. At the same time,the cord blood bilirubins between the hemolytic group and un-hemolytic group was compared,as well as the jaundiced group and the non-jaundiced group. Analyzed the characteristics of the cord blood bilirubins among different model of hemolysis three test.Result: 1.Incidence of ABO –HDN and hyperbilirubinemia : The higher of concentration of CBB,the higher of ABO –HDN and hyperbilirubinemia’s incidence.When the CBB concentration 》59.9μmol/L,the incidence of ABO- HDN and hyperbilirubinemia was 60% and90%,respectively.The difference has statistical significance among groups（P<0.01）.2. The area under the ROC curve for ABO –HDN detected by CBB was0.782±0.02（P<0.001,95%CI0.74,0.82）.The cut-off value of CBB for optimum prediction of ABO-HDN was 47.45μmol/L（ sensitivity 53.6%, specificity 91.8%）.3. The area under the ROC curve for hyperbilirubinemia detected by CBB was0.877±0.03（P<0.001,95%CI0.82,0.92）. The cut-off value of CBB for optimum prediction of hyperbilirubinemia was 40.8μmol/L（ sensitivity 85.1%, specificity 84.9%）.4. The jaundiced group had a higer mean CBB concentration（48.97±14.16μmol/L） than non-jaundiced group（40.27±10.17μmol/L）,P<0.01.5.The hemolytic group had a higer mean CBB concentration（42.77±8.25μmol/L）than non-phototherapy group（40.27±10.17μmol/L）,P<0.01.6.The concentrations of CBB and the incidence of hyperbilirubinemia in group of antibody release test positive was significantly higher than that in the group antibody release test negative（P<0.01）,but had no significant difference between Coombs’ test positive group and the other groups（P>0.05）. The different model of hemolysis three test had no reference value in predicating hyperbilirubinemia.Conclusion:1.Cord blood bilirubin level is useful in predicting neonatal hyperbilirubinnemia in infants with ABO-hemolytic disease.2.Cord blood bilirubin combined with hemolysis three test may help predict ABO-hemolytic disease,hyperbilirubinemia and phototherapy in the newborns whose mothers had blood types O.