Clinical Features Of Hyperbilirubinemia And Bilirubin Encephalopathy In Moderately Preterm Newborns

Hyperbilirubinemia is common in newborns, and bilirubin encephalopathy is the most serious complication, which usually causes permanent damage of central nervous system. Although moderately preterm newborns are at higher risk for bilirubin encephalopathy, they are often hospitalized for prolonged time, and accept more active interventions, which helps to protect them from bilirubin encephalopathy. However, bilirubin encephalopathy still occurs in our clinical practice in these gestational age group newborns. Bilirubin encephalopathy in preterm newborns usually doesn’t have typical clinical presentations, so it’s very difficult to diagnose in the early stage. Bilirubin encephalopathy in preterm newborns is often more complicated than that in term newborns, so central nervous system damage may occur in those who don’t have a very high serum bilirubin level. Therefore, it’s important to develop effective methods for the early prediction of bilirubin encephalopathy in premature infants and to prevent them from this devastating disease.Objective1. To compare clinical data of moderately preterm newborns with hyperbilirubinemia and bilirubin encephalopathy, and to provide a basis for the clinical intervention2. To compare clinical data of moderately preterm newborns with hyperbilirubinemia and bilirubin encephalopathy who have comparable serum bilirubin levels, and to make anfurther analysis of the clinical characteristics of these two conditions.Methods1. The study was conducted in neonatal department of the Children’s Hospital of Zhejiang University. Clinical information of newborns with gestational age between 30 and 35 weeks and a clinical diagnose of hyperbilirubinemia or bilirubin encephalopathy at discharge during January 1,2009 to December 31,2015 was collected.2. Analysis the data of basic information, causes of jaundiceg, laboratory,imaging and hearing examinations between the hyperbilirubinemia group and the bilirubin encephalopathy group.3 We selected cases in neonates in the hyperbilirubinemia group who have a similar serum total bilirubin level with those in the bilirubin encephalopathy group, and compared general information laboratory, imaging and hearing results..Results1.40439 sick newborns were admited to Children’s Hospital of Zhejiang University from 2009 to 2015. Of them,166 moderately preterm newborns were diagnosed hyperbilirubinemia and 12 were diagnosed bilirubin encephalopathy. There was significant difference in age, serum total bilirubin, indirect bilirubin values, serum albumin, B/A ratio, and hearing result between hyperbilirubinemia group and bilirubin encephalopathy group. The age at admission of the hyperbilirubinemia group was significantly lower than the bilirubin encephalopathygroup (7.11±7.92vs, 10.00±8.82days, p=0.040). The serum total bilirubin of the hyperbilirubinemia group was significantly lower than the bilirubin encephalopathy group (241.38±89.92 vs. 483.21±80.96 mol/L, p<0.001). The B/A ratio of the hyperbilirubinemia group was significantly lower than the bilirubin encephalopathy group (3.95±1.38 vs.7.80±1.19, p<0.001).2. Most moderately preterm newborns didn’t have specific reasons of hyperbilirubinemia. The most common four reasons of the hyperbilirubinemia group were infection (13.86%), birth abnormalities (6.63%), hypothyroidism(4.22%), and increased enterohepatic circulation (3.01%). While the most common four reasons of the bilirubin encephalopathy group were isoimmune haemolytic anaemia (5/12), extravascular hemolysis (4/12), infection (3/12), and G-6-PD deficiency (1/12).3. When with comparable TSB, there was no significant difference between two groups in gestational age, birth weight, clinical presentation of visible jaundice, duration of hospitalization, and serum albumin, while there was significant difference in admission age and B/A ratio. The admission age of the non-bilirubin encephalopathy group was significantly lower than the other group (7.11±7.92 vs 10.00±8.82days, p=0.040), and the B/A ratio of the non-bilirubin encephalopathy group was significantly lower than the other group (6.59±0.87 vs 7.47±0.93, p=0.037).Conclusion1. Moderately preterm newborns have lower incidence of hyperbilirubinemia than term infants, while they have similar incidence of bilirubin encephalopathy compared to term infants. Hyperbilirubinemia of moderately preterm newborns often doesn’t have specific reasons.2 Higher TSB and bilirubin albumin ratio are associated with bilirubin encephalopathy. In different hyperbilirubinemia moderately preterm newborn groups with comparable TSB, high B/A ratio is an important factor for developing bilirubin encephalopathy3. In moderately preterm newborns bilirubin encephalopathy usually don’t necessarily have typical MRI findings.