This month’s article focuses on the issue of jaundice in the newborn child.

Jaundice is a yellow colouration of the skin and sclerae (whites of the eyes) caused by the build-up of a chemical called bilirubin. Bilirubin is a bile pigment which is mainly produced from the breakdown of red blood cells. 

Bilirubin levels are higher in newborn children. This is because newborn babies have a higher concentration of red blood corpuscles. These corpuscles also have a shorter lifespan and break down more quickly in very young children. 

Terminology

For most babies, jaundice is completely harmless. This is called ‘physiological jaundice’. Physiological jaundice can occur in both breastfed and formula fed babies. 

Breastmilk jaundice is a type of physiological jaundice in breastfed babies, which can last for up to 12 weeks. 

Pathological jaundice is caused by a range of illnesses in the newborn baby. 

Jaundice is the most common condition of the newborn baby that requires medical attention. 

Approximately 60% of babies born at term will develop jaundice in the first week of their lives. While approximately 80% of babies before term (gestation age under 38 weeks) will develop jaundice in the first week of their lives. 

Causes of newborn jaundice

Physiological jaundice, the commonest cause of jaundice of the newborn, usually appears at two days of age, peaks between three to five days of age, and decreases by 10 days of age.

Breastmilk jaundice is a subtype of physiological jaundice apparent in breastfed babies – usually appears at two to four days of age, peaks at seven to 10 days of age, and can persist for up to 12 weeks. 

In both these situations the newborn baby will be well, will gain weight normally, and have normal urine and stools. 

Pathological jaundice is less common but important to recognise in order to treat potential underlying causes. There is a long list of these problems which can be grouped into the following categories:

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Genetic – includes rare conditions, Gilbert’s syndrome and Crigler-Najjar syndrome

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Anatomical – includes malformations of the liver and biliary tree, where bile becomes obstructed in the liver

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Metabolic –rare problems which include hypothyroidism and galactosaemia

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Infective – includes sepsis

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Blood group incompatibility – occurs when the newborn baby has a different ABO or rhesus blood group from the mother. This causes red blood corpuscles to break down (haemolysis). There are also other more rare causes of haemolysis

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Trauma – in this situation large areas of bruising in the child (such as can be associated with birth trauma for example cephalhaematoma after ventouse delivery) can also cause jaundice. 

Newborn babies with pathological jaundice will often develop the problem within the first 24 hours of their life, or after day six of the child’s life. These babies also tend to be unwell (which can lead to poor feeding, irritability and unusual sleepiness), with more widespread and obvious jaundice, and problems with dark urine and pale stools. 

Risk factors

Some newborns are at higher risk of developing jaundice. These factors include:

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Gestational age at birth under 38 weeks

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Breastfed babies

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A sibling with jaundice requiring treatment

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Male children

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Maternal age over 25

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Maternal diabetes mellitus

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European, Asian or Native American ethnicity.

Prognosis

For most babies, jaundice is not an indication of an underlying disease. Physiological jaundice is generally harmless and resolves by two weeks of age.

Breastmilk jaundice, in a baby who is otherwise well, is benign and self-limiting.

The prognosis for babies with jaundice due to an underlying condition depends on the cause. For example, surgical causes of jaundice (such as obstruction due to biliary atresia) are likely to resolve once the condition is treated. 

Complications

Complications in newborn children with jaundice are rare. A prospective surveillance study found a UK incidence of bilirubin encephalopathy of 0.9 per 100,000 live births.¹ A study in Ireland in 2010 found that 2.5% of infants had phototherapy and that none had complications.²

However, the chemical subgroup of bilirubin, which is called ‘unconjugated bilirubin’, is able to penetrate the blood-brain barrier, the membrane between the brain and the blood. This chemical can be toxic to the tissue of the brain and spinal cord, causing a condition known as bilirubin encephalopathy. 

The level at which bilirubin is likely to cause brain and spinal cord damage is variable and may be affected by a number of factors, which include the degree of prematurity, the rate of serum bilirubin increase, and co-existing illnesses in a newborn.  

A number of terms are used to describe the neurological consequences of raised bilirubin in the blood stream (hyperbilirubinaemia), these are: 

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Acute bilirubin encephalopathy – occurs when there is severe hyperbilirubinaemia. Children with this condition have problems that include lethargy, irritability, poor suck, abnormal muscle tone and posture (opisthotonus), high-pitched cry, apnoea and eventually seizures and coma

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Chronic bilirubin encephalopathy – a longer term problem which includes cerebral palsy, seizures, developmental delay, learning difficulties, vision and hearing problems, and dental dysplasia

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Kernicterus – describes the clinical features of either acute or chronic bilirubin encephalopathy and the pathological findings of deep yellow staining in the brain. 

Diagnosis 

In order to make a diagnosis of jaundice in the newborn, you should make a clinical observation at every contact, particularly within the first 72 hours. If the baby has one or more risk factors for developing significant hyperbilirubinaemia, ensure they are re-examined during the first 48 hours. Record your findings in the clinical notes:

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Examine the baby in bright, preferably natural light, for example in daylight by a window

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Look at the skin of the whole body and blanch to assess for jaundice (for example gently pressing on the nose)

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Also examine the whites of the eyes (sclerae), gums and palate

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Check for any signs of illness or fever

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Assess weight gain

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Evidence of bruising.

Assess how widespread the jaundice has become. Jaundice spreads from the head downwards in the newborn. Widespread jaundice may indicate a more severe problem, but cannot be relied on in isolation to assess severity.  

If there is doubt about the diagnosis, consider referral to a neonatologist or paediatrician for further assessment.

You should ask the baby’s mother about: 

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Obstetric history (including the mother’s rhesus status and blood group if known) and the baby’s gestational age at birth

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Age at onset and duration of jaundice

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Feeding history (type of feeding and whether there have been any problems with adequate intake)

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Number of wet or dirty nappies in a day (to assess the state of hydration)

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Also specifically ask about the presence of dark urine and/or pale stools

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Signs of illness (for example lethargy, fever, vomiting, significant weight loss, irritability)

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Family history of relevant conditions – for example significant haemolysis (including glucose-6-phosphate-dehydrogenase deficiency). Ask whether any siblings or close family members have required hospital treatment such as phototherapy or exchange blood transfusion for neonatal jaundice.

You should also offer parents and carers information on:

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How to check the baby for jaundice

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What to do if they suspect jaundice

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The importance of recognising jaundice in the first 24 hours

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Observing for signs of adequate hydration

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The importance of checking the baby’s nappies for dark urine or pale stools.

Management

Arrange emergency admission (via 999 ambulance) if there is jaundice with features of bilirubin encephalopathy (for example atypical sleepiness, poor feeding or irritability).

Arrange urgent admission to a neonatal or paediatric unit (depending on local arrangements) within two hours if jaundice first appears at less than 24 hours of age.

Arrange urgent admission to a neonatal or paediatric unit (depending on local arrangements) as soon as possible and to be seen within six hours (using clinical judgement regarding more urgent referral or admission) if:

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Jaundice first appears at more than seven days of age

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The neonate is unwell (for example lethargy, fever, vomiting or irritability)

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Gestational age of less than 35 weeks

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Prolonged jaundice is suspected – that is a gestational age of less than 37 weeks with more than 21 days of jaundice; or a gestational age of 37 weeks or more with more than 14 days of jaundice

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Poor feeding and/or concerns about weight, particularly in breastfed infants

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Pale stools and dark urine.

For all other jaundiced neonates:

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If transcutaneous bilirubin measurements are available in primary care, record the level within six hours and manage according to local protocols

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If transcutaneous bilirubin measurements are unavailable in primary care, refer to a neonatal or paediatric unit for measurement of a serum bilirubin level within six hours. Do not rely on visual assessment of jaundice to guide management.

If admission is not necessary, reassure parents and carers that:

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Neonatal jaundice is common and is usually temporary and harmless

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Breastfeeding can usually continue.

Treatments

The choice of treatment in secondary care will depend on a number of factors, including the underlying cause of the jaundice. Treatment options include:

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No treatment – this may be appropriate for well newborn children with physiological or breastmilk jaundice and a bilirubin level below the treatment threshold

• Treatment of any underlying illness (such as infection), with as follows:

– Phototherapy, absorption of light through the skin converts unconjugated bilirubin into products that are more easily excreted in the stool and urine

– Exchange transfusion, indicated if the baby has signs of bilirubin encephalopathy and considered if the risk of kernicterus is high or jaundice is not responding to phototherapy

– Early surgical treatment, required for conditions such as biliary atresia.

References

1. Manning D, Todd P, Maxwell M, Platt MJ. Prospective surveillance study of severe hyperbilirubinaemia in the newborn in the UK and Ireland. Arch Dis Child Fetal Neonatal Ed. 2007 Sep; 92(5): F342-F346
2. Walsh SA, Murphy JF. Neonatal jaundice – are we over-treating? Ir Med J. 2010 Jan; 103(1): 28-29
3. National Institute for Health and Care Excellence. Jaundice in newborn babies under 28 days NICE Guidelines [CG98] Published May 2010. Available from: https://www.nice.org.uk/guidance/cg98 [Accessed January 28, 2016]