Jaundice is an essential problem in neonates in the first week of life. High bilirubin levels may be toxic to the developing central nervous system and may cause neurological impairment even in term newborns. 

Nearly 60% of term newborns become visibly jaundiced in the first week of life. In most cases, it is benign, and no intervention is required. Approximately 5-10% of them have clinically significant jaundice requiring the use of phototherapy or other therapeutic options. 

For NEET PG aspirants, it is crucial to have a clear understanding of neonatal jaundice, including its causes, symptoms, treatments, and other crucial factors. 

Keep reading for detailed insight!

What is Neonatal Jaundice?

Neonatal jaundice is a yellowish discolouration of a newborn’s skin and eyes caused by elevated bilirubin. It is a pretty normal condition; nearly 60 percent of full-term infants and almost 80 percent of infants in the first week exhibit some degree of jaundice.

In most cases, physiological jaundice is a temporary condition that becomes normal as the newborn’s liver matures. It usually appears on the second day of life, peaks on days 2-5, and clears by weeks 2-3. 

In comparison, jaundice occurring within 24 hours of birth or after 23 weeks is pathologic, indicating an underlying issue.

It is typically caused by unconjugated bilirubin; any increase of direct (conjugated) bilirubin is regarded as pathologic. Being aware of these fundamentals can lead to accurate assessments and prompt treatment.

What are the Causes of Neonatal Jaundice?

Newborns naturally have a lot of bilirubin from rapid RBC turnover and an immature liver. A full-term baby’s liver has only ~1% of the adult UGT enzyme activity, so it can’t clear bilirubin quickly. This physiologic cause means bilirubin can build up in the first few days. 

Important causes of jaundice in neonates include:

1. Hemolytic: Rh incompatibility, ABO incompatibility, G6PD deficiency, thalassemias, hereditary spherocytosis 
2. Non-hemolytic: Prematurity, extravasated blood, inadequate feeding, polycythemia, idiopathic, breast milk jaundice 

Beyond that, a variety of factors can raise bilirubin further:

• Haemolysis (red cell breakdown): Immune causes, such as ABO or Rh incompatibility, can cause rapid haemolysis in the baby. Red cell defects (or hemoglobinopathies), which augment bilirubin production, are also non-immune.
• Birth Trauma: Delivery causes large bruises or cephalohematomas, which release additional bilirubin during the breakdown of blood. The risk also increases with subgaleal haemorrhage and polycythaemia.
  
• Immature Liver Clearance: Failure to conjugate bilirubin is caused by a genetic enzyme (e.g., Gilbert or Crigler-Najjar syndromes) or a slowness of activity of UDP-glucuronosyltransferase. Any disease that interferes with the liver of the newborn (such as hypothyroidism or inborn errors of metabolism) may contribute.
  
• Breastfeeding Jaundice: One-third of all breastfed babies are detected to have mild clinical jaundice in the third week of life, which may persist into the 2nd to 3rd month of life in a few babies. 

This increased frequency of jaundice in breastfed babies is not related to characteristics of breast milk but rather to inadequate breastfeeding (breastfeeding jaundice). 

• Breast Milk Jaundice: Approximately 2-4% of exclusively breastfed term babies have jaundice over 10 mg/dl beyond the third-fourth weeks of life. These babies should be investigated for prolonged jaundice. A diagnosis of breast milk jaundice should be considered if this is unconjugated, and other causes for prolongation have been ruled out.

Mothers should be advised to continue breastfeeding at frequent intervals, as total serum bilirubin (TSB) levels usually decline over time. Breastfeeding should not be stopped either for diagnosis or treatment of breast milk jaundice. 

• Congenital Metabolic Disorders: Rare chromosomal syndromes like Patau syndrome (trisomy 13) have been reported with cholestatic neonatal jaundice. This underscores that conjugated jaundice is almost always a pathologic condition.

What are the Risk Factors of Neonatal Jaundice?

Risk factors for the development of severe hyperbilirubinemia include:

1. Jaundice, if observed in the first 24 hours after birth. 
2. Blood group incompatibility with a positive direct antiglobulin test or other known hemolytic disease (e.g., G6PD deficiency).
3. Gestational age 35-36 weeks. 
4. The previous sibling received phototherapy. 
5. If breastfeeding is inadequate, there is excessive weight loss.

In practice, any newborn with these risk factors is monitored closely.

What are the Symptoms of Neonatal Jaundice?

The hallmark sign of neonatal jaundice is the yellowing of the skin and sclera. Initially described by Kramer, dermal bilirubin staining can be used as a clinical guide to determine the level of jaundice. 

Dermal staining in newborns progresses in a cephalocaudal direction. The newborn should be examined in good daylight. Additionally, the skin of the forehead, chest, abdomen, thighs, legs, palms, and soles should be blanched with digital pressure, and the underlying colour of the skin and subcutaneous tissue should be noted.

Other symptoms may not be noticeable initially, but severe jaundice can cause signs of neurologic involvement or dehydration. Watch for lethargy, poor feeding, a high-pitched cry, or a floppy tone. These symptoms warrant urgent evaluation. Also note if jaundice persists beyond two weeks (unless it is due to breast milk jaundice) or if bilirubin levels rise rapidly.

How is Neonatal Jaundice Diagnosed?

Diagnosis involves measuring bilirubin levels. Most hospitals screen newborns with a bilirubinometer and follow up with a blood test to measure total serum bilirubin (TSB) and its fractionation. 

Serum levels of total bilirubin are approximately 4-6 mg/dl (zone 1), 6-8 mg/dl (zone 2), 8-12 mg/dl (zone 3), 12-14 mg/dl (zone 4), and >15 mg/dl (zone 5).

The aim of performing investigations is to confirm the level of jaundice, identify the cause, and follow the response to treatment. 

First Line 

• Total Serum Bilirubin: All cases with suspected pathological levels, either clinically or by transcutaneous measurements, need confirmation by blood examination of serum bilirubin levels. 
• Blood Groups of Mother and Baby (if the mother is ‘O’ or Rh negative): Detects any incompatibility. 
• Peripheral Smear: Evidence of haemolysis.  

Second Line 

• Direct Coombs test: Detects the presence of antibody coating on fetal RBCs. 
• Haematocrit: Decreased in haemolysis. 
• Reticulocyte Count: Increased in haemolysis. 
• G6PD Levels in RBC 
• Others: Sepsis screen; thyroid function test; urine tests to detect reducing substances to rule out galactosemia; specific enzyme/genetic studies for Crigler-Najjar Syndrome. 

If bilirubin is predominantly direct (conjugated) >1 mg/dL, further workup (liver function tests, ultrasound) is indicated because this form of jaundice is always pathologic.

What are the Treatment Options for Neonatal Jaundice?

Most cases of neonatal jaundice are mild and resolve with simple measures. Frequent breastfeeding helps the baby eliminate bilirubin through the stool and urine. If bilirubin levels are moderate, phototherapy is the first-line treatment. 

1. Phototheraphy

Under phototherapy, the baby wears only a diaper and special eye protection and lies under blue-spectrum lights. The light converts bilirubin into a soluble form that the baby can excrete in urine. 

Mechanisms Include:

• Configurational isomerisation (reversible, 25% of TSB, slow excretion)
• Structural isomerisation (irreversible to lumirubin, 2–6% of TSB, rapid excretion—primary mechanism)
• Photo-oxidation (minor pathway, urinary excretion)

Types of lights: 

CFLs (commonly used in India), halogen, LEDs (preferred for longevity and high irradiance), and fibre-optic sources.

Monitoring:

• Check baby’s temperature every 2–4 hr
• Assess TSB every 12–24 hr
• Stop when two TSB values 12 hr apart are below age-specific cutoffs
• Monitor for rebound, especially in haemolysis cases

2. Exchange Transfusion

Double volume exchange transfusion (DVET) should be performed if the TSB levels reach the age-specific cut-off for exchange transfusion or the infant shows signs of bilirubin encephalopathy, irrespective of TSB levels. Indications for DVET at birth in infants with Rh isoimmunization include:

• Cord bilirubin is 5 mg/ dl or more 
• Cord Hb is 10 g/ dl or less 

At birth, if a baby shows signs of hydrops fefalis or cardiac decompensation in the presence of a low PCV (<35%), a partial exchange transfusion with 50 mL/kg of packed red blood cells should be performed to quickly restore the blood’s carrying capacity. Exchange transfusion (ET) should be performed by the pull and push technique using the umbilical venous route. The umbilical catheter should be inserted just enough to get a free flow of blood. 

What are the Prevention Measures of Neonatal Jaundice?

Neonatal jaundice can be prevented by following the mentioned key points:

• Antenatal investigation should include maternal blood grouping. A Rh-positive baby born to a Rh-negative mother is at higher risk for hyperbilirubinemia and requires greater monitoring. Anti-D injection after the first obstetrical event helps reduce the risk of sensitisation in future pregnancies. 
• Ensuring adequate breastfeeding 
• Parent education regarding danger signs should include yellowish discolouration below the knees and elbows, or persistent jaundice beyond 15 days, as a reason for an immediate checkup by health personnel. 
• High-risk babies, such as those with large cephalohaematoma or a family history of jaundice, should be followed up after 2-3 days of discharge.

FAQs About Neonatal Jaundice

1. What are the types of neonatal jaundice? 

The most common are physiological jaundice, breastfeeding jaundice, breast milk jaundice, haemolytic jaundice (due to Rh or ABO incompatibility), and infection-related jaundice, or that caused by liver disease.

2. What is the difference between physiological and pathological jaundice? 

Physiological jaundice in newborns is common and typically appears on the second day of life, peaks on days 2-5, and clears by weeks 2-3. Meanwhile, pathological jaundice in newborns emerges in less than one day, accelerates or prolongs itself, demanding timely examination and medication.

3. What is kernicterus? 

Kernicterus is a rare but severe case of brain damage caused by excess bilirubin crossing the blood-brain barrier. Without treatment, it may cause permanent disability or death.

4. How often should bilirubin levels be checked? 

The frequency varies with baby age and condition, but on average, it is checked every 12-24 hours during phototherapy, or more often in cases of higher levels or rapidly rising levels.

5. Are there any side effects of phototherapy? 

Potential mild side effects can be skin rash, dehydration, diarrhoea, and skin bronzing in some people with particular liver disorders.

Conclusion

Although a common condition in newborns, it needs to be identified early and managed accordingly to avoid the eventual occurrence of conditions like kernicterus and permanent neurological deformities. Whether the underlying causes are physiological or pathological, it is essential to make treatment decisions, including phototherapy and exchange transfusion.

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