Neonatal Jaundice
Dezhi Mu MD/PhD
Department of Pediatrics, West China Second University Hospital, Sichuan University
Introduction
Jaundice is quite common (5mg/dl).
Full term infants: at least 50%
Preterm infants: over 80%
Elevated blood bilirubin levels: 97%
Introduction continued
When? in the first week of life
Where? skin , mucosa and white of eye
How many? blood bilirubin concentrations is ≥5-7mg/dl.
Introduction continued
Producing
Excreting
Why Jaundice occurred?
Bilirubin Metabolism:
1. RBC: Heme bilirubin (UCB) 2. Blood: carried by bound to albumin3. Liver: uptaken : Y protein, Z protein conjugated: UDPGT excreted : to the biliary system 4. Intestine: stercobilins -glucuronidase
enterohepatic circulation
The metabolic characteristics of bilirubin in newborns:
1. Bilirubin production
8.8mg/Kg/d in newborns
3.8mg/Kg/d in adults
2. Bilirubin-albumin complex formation
a. preterm infant;
b. acidosis
3. Bilirubin metabolism of hepatocyte
a. Hepatic uptake of bilirubin
b. Bilirubin conjugation:
UDPGT (uridine diphosphate
glucoronyl transferase)
c. Defective bilirubin excretion
ability to bile system
4. Enterohepatic circulation
The metabolic characteristics of bilirubin continued
Bilirubin toxicity
1. Conjugated bilirubin
water-soluble
2. Unconjugated bilirubin
lipid-soluble
bilirubin-encephalopathy
( kernicterus )
Clinical Manifestations
Jaundice appears
When:
at any time during the neonatal period
Where:
from face chest
abdomen feet
Evaluation of jaundice :
1. By eyes: face, 5mg/dl ( 85μmol/L ); abdomen, 10-15mg/dl; feet, 15-20mg/dl ;2. By transcutaneous measurement : used for screening3. By serum levels : standard
Manifestations continue
Classification:
Physiological Jaundice
Pathological Jaundice
Manifestations continue
Physiological jaundice : 1. General state is well
2. Appears 2-3days (>24h of age) peaks < 12.9mg/dl (full term
infants) <15mg/dl (preterm infants) fades <2 week (term infants) <4 weeks (preterm infants)
3. Accumulates <5mg/dl/d 4. Direct bilirubin <2mg/dl
Manifestations continue
Pathological Jaundice 1. Appears earlier (first 24 hours of
life)2. Peaks >12.9mg/dl (full term
infants) >15mg/dl (preterm infants) Fades >2 weeks (term infants)
>4 weeks (preterm infants)3. Accumulates >5mg/dl/d4. Direct bilirubin >2mg/dl
5.Jaundice recurrent
Manifestations continue
Common causes of pathological jaundice
1. Unconjugated bilirubinemia: a. hemolytic diseases: ABO, Rh incompatibility b. G-6-PD deficiency; c. Breast milk jaundice
2. Conjugated bilirubinemia: a. Neonatal hepatitis
b. Biliary obstruction (cholestatic jaundice)
biliary atresia,
common bile duct stenosis
c. Congenital metabolic diseases
α-1 antitrypsin deficiency
Causes of pathological jaundice continue
Hemolytic disease of newborn
Hemolytic disease:
ABO: 85.3%Rh : 14.6%MN : 0.1%
Hemolytic disease of newborn continued
ABO incompatibility the mother: type O the infant: type A
or B Rh incompatibility the mother : Rh ( - ) the infant: Rh ( + ) D,E,C,d,e,c
Pathogenesis
Pathophysiology
Red blood cell breakdown
Hyperbilirubinemia
Jaundice
Kernicterus
Seizures etc.
Anemia
1. Liver
2. Spleen
3. Heart, other organs
4. Hydrops
Clinical Manifestations:ABO Rh
1.Jaundice : mild severe 1-2 day 24 h
2.Anemia: mild severe
(3-6 weeks) heart failure
3.Hepato- rare common
splenomegaly
Complication
Kernicterus:
Phase 1: decreased alertness
Hypotonia
Poor feeding
Phase 2: Hypertonia,
Retrocollis, opisthotonus
Phase 3: Hypotonia
1. Blood type incompatibility
2. Hyperbilirubinemia :
Unconjugated bilirubin level
3. Hemolytic tests
1). Hemoglobin level : low
2). Reticulocytes:10–15%
3). Nucleated RBC
Laboratory tests:
Antibody test
1). Direct Coombs test (+) confirm
2). Antibody release test (+) confirm
3). Free antibody test (+) judge
Laboratory tests continued
1). Phototherapy
2). Exchange transfusion
3). Internal Medicine
Treatments
During pregnancy
1. Intrauterine blood
transfusion
2. Early delivery
Treatments continued
After birth 1. Phototherapy Principle : photon of light Three photochemical reactions: 1). Structure isomer 2). Geometric isomer 3). Photo-oxidation
Photoproducts excretion: w/o conjugation
Treatments continued
Indications of phototherapy :
Unconjugated bilirubinemia
Bilirubin level >12mg/dl
Light source:
Spectral outputs 420 to 500nm
Treatments continued
Side effects of phototherapy :
a. diarrhea
b. fever
c. skin rash
d. bronze baby syndrome
(conjugated bilirubin>4mg/dl)
Treatments continued
2. Exchange Transfusions:
a. Severe hemolytic disease
b. Refractory to phototherapy
Treatments continued
Aims of transfusions:
a. Remove antibodies
b. Remove bilirubin
c. Correct anemia
Treatments continued
Indication of transfusions:
one of the follows
a. 20mg/dl (340 μmol/L)
b. >4mg/dl,Hgb<120g/L, edema
c. 0.7mg/dl/h
d. Kernicterus
Treatments continued
Source of the blood
mother newborns
For Rh: Rh ABOincompatibility
For ABO: “AB” plasma “O” cells
incompatibility packed RBC
Treatments exchange transfusions
Potential complications:
a. Infection
b. Necrotizing enterocolitis NEC
c. Thromboembolic complications
Treatments exchange transfusions
3. Pharmacological agents:
a. Phenobarbital
Effects: Uptake, Conjugation
Excretion
b. Albumin
c. IVIG
Treatments continued
Preventions
For ABO incompatibility: No
For Rh incompatibility
300 μg of human anti-D globulin within 72 h of delivery.
1.Unconjugated bilirubinemia:
a. Hemolytic diseases:
ABO, Rh incompatibility
b. G-6-PD deficiency;
c. Breast milk jaundice
1.Unconjugated bilirubinemia:
b. G-6-PD deficiency;
male, jaundice, enzyme activity
c. Breast milk jaundice causes: unclear, -
glucuronidase follows physiologic jaundice: 4-7
d breast feeding persist for several weeks.
Conjugated bilirubinemia:2.Conjugated bilirubinemia:
a. neonatal hepatitis
b. biliary obstruction (cholestatic
jaundice)
biliary atresia,
common bile duct stenosis
c. congenital metabolic diseases
α-1 antitrypsin deficiency
Case analysis :
24 old male infant, gravida1,para 1.
Apgar scores: 8 at 1 min
Mother: blood type “O”
PE: icterus appeared on
face and trunk skin
liver edge 1cm
palpable spleen tip
Case analysis continued
Lab tests:
Hgb:13g/dl, reticulocyte count : 7%
Blood smear: nucleated RBC
Blood type: A, Rh-positive
Serum bilirubin: 12.9mg/ml
Direct Coomb’s test: weakly positive
Question: what’s the risk factor ?
Thank you! Questions ?
Department of Pediatrics