The Metabolic Characteristics of Bilirubin in Newborns Wu jinlin Department of Pediatrics West China Second University Hospital Sichuan University Baby on Phototherapy Introduction of Neonatal Jaundice  Jaundice.

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Transcript The Metabolic Characteristics of Bilirubin in Newborns Wu jinlin Department of Pediatrics West China Second University Hospital Sichuan University Baby on Phototherapy Introduction of Neonatal Jaundice  Jaundice.

Slide 1

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 2

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 3

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 4

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 5

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 6

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 7

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 8

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 9

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 10

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 11

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 12

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 13

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 14

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 15

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 16

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 17

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 18

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 19

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 20

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 21

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 22

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 23

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function


Slide 24

The Metabolic Characteristics of
Bilirubin in Newborns
Wu jinlin
Department of Pediatrics
West China Second University Hospital
Sichuan University

Baby on Phototherapy

Introduction of Neonatal Jaundice
 Jaundice is quite common in neonatal period
[1] 60% of term infants and 80% of preterm infants
[2] Visible jaundice from sclera, mucosa and skin

Introduction of Neonatal Jaundice
 Can cause serious consequences
respiratory failure
[1] Actue phase

bilirubin encephalopathy

neonatal death

[2] lifelong neurologic sequelae— kernicterus
cerebral palsy
epilepsy
mental retardation
auditory and visual
disfunctions

Why jaundice is so prevalent
in neonatal period ???

The Metabolic Characteristics of

Bilirubin in Newborns

Albumin

shunt
bilirubin

Y&Z protein
UDPGT
β-glucuronidase

Enterohepatic
Circulation
Normal Bilirubin Metabolism

What’s the distinct metabolic
characteristics of bilirubin in
newborns comparing

with our adults?

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

1. Increased bilirubin production
(1) Increased oxygen partial pressure

PO2

PO2

RBC

bilirubin

RBC

1. Increased bilirubin production

(2) Short survival of neonatal erythrocyte
Preterm: ﹤70 days
[1] Life span of RBC

Term: 80 days

Adult: 120 days
[2] Turnover rate of neonatal hemoglobin:
2 times faster than that of adults

1. Increased bilirubin production
(3) Over production of shunt bilirubin

heme
shunt bilirubin
bone marrow precusor

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2.Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

2. Insufficient Binding between Bilirubin and Albumin
 low content of serum albumin

GA
albumin
bilirubin-albumin complex
 different degree of
acidosis at birth
binding affinity

A

A
serum

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3.Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5. Others

3. Deficient Bilirubin Conjugation in the Hepatocyte
 Y carrier protein
increases rapidly
5~10 days later

 UDPGT
reaches the adult’s
values 1 week
after birth

conjugation of
bilirubin with
glucuronic acid

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4.Increased enterohepatic circulation of bilirubin
5. Others

4. Increased Enterohepatic Circulation of Bilirubin
intestinal flora is not fully
developed
abundant β-glucuronidase

delayed excretion of meconium

Neonatal Bilirubin Metabolism
1. Increased bilirubin production in newborns

2. Insufficient binding between bilirubin and albumin
3. Deficient bilirubin conjugation in the hepatocyte
4. Increased enterohepatic circulation of bilirubin
5.Others

5. Others
cephalohematoma
dehydration

hunger

……

intracranial
hemorrhage
acidosis

hypoxia

Summary
[1] Jaundice is much more frequent in neonates
[2] Pathogenesis : over-production of bilirubin
immature liver function