脐血胆红素预测新生儿黄疸的意义

目的研究脐带血胆红素水平预测足月健康新生儿后续黄疸程度的价值。方法523例足月健康新生儿,测定脐血胆红素、白蛋白水平,监测每日经皮胆红素值（TCB）。对时龄0—24hTCB≥18;-48hTCB≥21;-72hTCB≥25;〉72h≥25者,送检静脉血血清胆红素值（TSB）,考虑是否需要光疗。将新生儿按脐血胆红素水平分为〈30μmol／L;≥30μmoL／L;≥36μmol／L;≥42μmoL／L,共4组。比较4组新生儿TCB≥25、TSB〉205μmol／L、TSB〉257μmoL／L及需要光疗的发生率。对脐血胆红素水平预告新生儿黄疸进行分析。比较黄疸组新生儿和非黄疸组新生儿临床特征。结果脐血胆红素水平升高,各组新生儿TCB≥25、TSB〉205μmol／L、TSB〉257μmoL／L和需要光疗的发生率增加。脐血胆红素水平用于预测新生儿黄疸发生有统计学意义（P〈0．001）。黄疸组新生儿脐血胆红素值显著高于非黄疸组（t=10．96,P〈0．001）。而脐血清白蛋白值（t=2．38,P〉0．05）、妊娠周数（t=-0．90,P〉0．05）、出生体重（t=0．10,P〉0．05）比较,两组均无统计学差异。结论脐血胆红素水平用于预测足月健康新生儿后续黄疸的程度是一种有效的方法。

Predictive value of umbilical cord blood bilirubin level for subsequent neonatal jaundice

OBJECTIVE: To investigate the predictive value of umbilical cord serum (UCS) bilirubin for subsequent jaundice in healthy term newborns. METHODS: Five hundred and twenty-three healthy term newborns (275 boys, 248 girls) were selected. The cord blood total serum bilirubin concentration and the serum albumin concentration were determined. All the infants were assessed for jaundice daily by measurement of transcutaneous bilirubin (TCB). When the infant's TCB was >or= 18 within the first 24 h after birth, >or= 21 at 48 h, >or= 25 at or after 72 h, the venous total serum bilirubin (TSB) was determined and treatment against jaundice was applied as needed. The infants were aligned into four groups according to their UCS bilirubin levels, starting from < 30 micromol/L(group 1); >or= 30 micromol/L(group 2); >or= 36 micromol/L(group 3); >or= 42 micromol/L(group 4). The frequency of hyperbilirubinemia and phototherapy (PT) were compared among the four groups. An analysis of UCS bilirubin as a predictor of later development of jaundice was performed. The characteristics of the infants who became jaundiced (jaundiced group) were compared with the normal infants (non-jaundiced group). RESULTS: A clear correlation between UCS bilirubin level and the development of hyperbilirubinemia was found in all populations of the four groups. Only eight of the 194 infants in group 1 showed a TCB index >or= 25. TSB values > 205 micromol/L but < 257 micromol/L were observed in 2 newborns. None of the infants in this group showed TSB > 257 micromol/L or needed PT. Thirty-two infants in group 2 showed TCB >or= 25, 12 infants had TSB > 205 micromol/L but < 257 micromol/L, 2 infants had TSB > 205 micromol/L and received PT. In group 3, one infant developed hyperbilirubinemia at 48 h after birth and received PT. Thirty-nine infants showed TCB >or= 25, 16 infants TSB > 205 micromol/L but < 257 micromol/L, 2 infants had TSB > 205 micromol/L and also received PT. In group 4, 4 infants showed a range of TSB from 200 to 215 micromol/L at 48 h and received PT. Twenty-two infants showed TCB >or= 25, 17 of them showed TSB > 205 micromol/L but < 257 micromol/L, and 5 of them had TSB > 205 micromol/L and received PT. The frequency of TSB > 205 micromol/L increased from 1.03% in group 1, 5.77% in group 2, 19.75% in group 3 and to 42.5% in group 4. None of the 194 newborns in group 1 needed phototherapy, whereas 0.96%, 3.70% and 22.5% of the newborns in groups 2 - 4, needed PT. The frequency of patients with hyperbilirubinemia or phototherapy increased with increasing UCS bilirubin levels. For the prediction of TCB >or= 25 using a UCS bilirubin cut-off level, such as >or= 35 micromol/L, we found a positive predictive value of 45.68% and sensitivity of 68.27%. It is significant to predict neonatal jaundice by UCS bilirubin levels (P < 0.001). In the jaundiced group (TCB >or= 25) UCS bilirubin levels were significantly higher than those in the non-jaundiced group (t = 10.96, P < 0.001). No significant differences were found in the cord blood serum albumin concentration (t = 2.38, P > 0.05), the gestational age (t = -0.90, P > 0.05), and birthweight (t = 0.10, P > 0.05) between the jaundiced and non-jaundiced groups. CONCLUSIONS: UCS bilirubin level is useful in predicting the subsequent jaundice in healthy term infants. The use of UCS bilirubin values may help detect infants at low or high risk for hyperbilirubinemia and minimize an unnecessary prolongation of hospitalization.