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PHYSIOLOGICAL NEONATAL JAUNDICE

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OBJECTIVES

1) TO DESCRIBE PHYSIOLOGICAL NEONATAL JAUNDICE

2) TO DESCRIBE THE MECHANISM OF PHYSIOLOGICAL NEONATAL JAUNDICE

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Neonatal jaundice

Unconjugated bilirubin

Pathologic

Hemolytic

Intrinsic causes

Extrinsic causes

Non-hemolytic Physiological

jaundice of Neonates

Conjugated bilirubin

Hepatic

Post-hepatic

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INTRODUCTIONMost infants (60%) develop visible jaundice

due to elevation of unconjugated bilirubin concentration during their first week. This common condition is called Physiological Neonatal Jaundice.

Yellowing of the skin and other tissues of a newborn infant.

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PHYSIOLOGICAL NEONATAL JAUNDICE

PATHOLOGICAL NEONATAL JAUNDICE

Appears after 24 hours. Appears within 24 hours.

Increase bilirubin < 5mg/dl

Increase bilirubin > 5mg/dL per day at the rate of 0.2mg/dL per hour

Clinically not detectable after 14 days.

Jaundice persist after 14 days.

Disappears without treatment.

Need treatment according to the cause.

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MECHANISM OF NEONATAL JAUNDICE1.More bilirubin producedDestruction of HbFShorter life span of fetal red blood cells, being

approximately 80 to 90 days in a full term infant, compared to 100 to 120 days in adults.

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MECHANISM OF NEONATAL JAUNDICE

2.The low capability of albumin on unconjugated bilirubin transportation

acid intoxication

Less albumin in neonates

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MECHANISM OF NEONATAL JAUNDICE

3.The low capability of hepatocytesLess Y protein and Z protein The primary development of Hepato-

enzyme systemEasy-broken hepato-enzyme systemAfter-born, the blood glucose level is very

low.

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MECHANISM OF NEONATAL JAUNDICE4.High workload of the hepato-enteric circulationLess bacterial (low conversion of bilirubin

to urobilinogen by the intestinal flora)

Low enzymatic activity in intestine ( UDP glucuron yltransferase )

High level of bilirubin in meconium

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BREAST MILK JAUNDICE

• Whereas breast feeding jaundice is a mechanical problem, breast milk jaundice is a biochemical occurrence and the higher bilirubin possibly acts as an antioxidant. Breast milk jaundice occurs later in the newborn period, with the bilirubin level usually peaking in the sixth to 14th days of life. This late-onset jaundice may develop in up to one third of healthy breastfed infants.

BREAST MILK JAUNDICE• First, at birth, the gut is sterile, and normal gut flora takes time

to establish. The bacteria in the adult gut convert conjugated bilirubin to stercobilinogen which is then oxidized to stercobilin and excreted in the stool. In the absence of sufficient bacteria, the bilirubin is de-conjugated by brush border β-glucuronidase and reabsorbed. This process of re-absorption is called enterohepatic circulation. It has been suggested that bilirubin uptake in the gut (enterohepatic circulation) is increased in breast fed babies, possibly as the result of increased levels of epidermal growth factor (EGF) in breast milk.Breast milk also contains glucoronidase which will increase deconjugation and enterohepatic recirculation of bilirubin.

BREAST MILK JAUNDICE• Second, the breast-milk of some women contains a

metabolite of progesterone called 3-alpha-20-beta pregnanediol. This substance inhibits the action of the enzyme uridine diphosphoglucuronic acid (UDPGA) glucuronyl transferase responsible for conjugation and subsequent excretion of bilirubin. In the newborn liver, activity of glucuronyl transferase is only at 0.1-1% of adult levels, so conjugation of bilirubin is already reduced. Further inhibition of bilirubin conjugation leads to increased levels of bilirubin in the blood. However, these results have not been supported by subsequent studies.

BREAST MILK JAUNDICE

• Third, an enzyme in breast milk called lipoprotein lipase produces increased concentration of nonesterified free fatty acids that inhibit hepatic glucuronyl transferase, which again leads to decreased conjugation and subsequent excretion of bilirubin.

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SUNLIGHT EXPOSER THERAPY

• Bilirubin can absorb blue light( 420nm-470nm)• Toxic unconjugated bilirubin is converted into

nontoxic unconjugated bilirubin( lumirubin) which is the isomers and this non-toxic unconjugated bilirubin is easily excreted through kidney.

• Finally bilirubin level will be low.• All the body parts need to be exposed but might be

harmful and harmful rays also falls on the body.

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SUMMARY Increased RBC

Shortened RBC lifespan

Immature Hepatic uptake & conjugation

Increased EnterohepaticCirculation

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SUMMARY

Physiological neonatal jaundice is a very common condition in which there is increase in bilirubin in neonates.

Disappears without treatment after around 14 days.

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