Prediction of hyperbilirubinaemia in the healthy term newborn

The aim is to establish the correlation between transcutaneous bilirubin (TCB) and serum bilirubin (TSB) and its predictive value for significant hyperbilirubinaemia > or = 290 mcmol/L (17 mg/dL). We studied a total of 2004 healthy full-term newborns, weight 3.230 g +/- 491 g; 90% received breast milk. The study was performed in two phases. In the first phase (610 newborns), the following tests were carried out: hematocrit and bilirubin in umbilical cord blood; TCB at 24 h, 48 h and between 60 h and 96 h at the forehead and over the sternum; TSB was measured along with this last test. In the second phase (1394 newborns), the predictive value of TCB and TSB was validated. The incidence of bilirubin > or = 290 mcmol/L was 2.95% and 3.2%. The correlation between TSB and TCB is high (n = 996; r = 0.92; y = 5.916 + 0.804x; p < 0.000). There was a better correlation between TCB and TSB with sternal compared to forehead determination (< 24 h: 0.81 vs 0.77; 24-48 h: 0.887 vs 0.83; and > 48 h: 0.94 vs 0.83). The study showed the scant sensitivity of umbilical cord blood bilirubin and good predictive value at 24 h of TSB > or = 102 mcmol/L (6 mg/dL) and at 48 h of TSB > or = 154 mcmol/L (9 mg/dL) and TCB > or = 13 (equivalent to 154 mcmol/L).

There is a good correlation between TCB and TSB. In infants with TSB > or = 102 mcmol/L at 24 h or TSB > or = 154 mcmol/L or transcutaneous readings > or = 13 h at 48 h, a TSB test must be performed after 48 h of life.