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