What Is Jaundice In Newborns?

Overview

Newborns (neonates) are babies in their first 28 days of life.

Jaundice is the yellow discolouration of the sclerae (whites of the eyes) or skin. It can be alarming to see jaundice in a newborn, but it isn’t always a cause for serious concern. Sometimes, neonatal jaundice is normal and resolves itself, but at other times, neonatal jaundice can indicate a serious health problem and requires urgent intervention to prevent long-term complications.

This article will explore the potential causes of jaundice in a baby.

Types of jaundice in newborns

There are two broad types of jaundice in newborns: physiological jaundice and pathological jaundice.

Physiological jaundice is common and presents after the first 24 hours of life. It is a transient condition, with most cases developing on the second or third day after birth and resolving by the end of the second week of life.¹ Any cases of physiological jaundice that last longer than 14 days are deemed to be cases of prolonged jaundice and can be due to breast milk jaundice if occurring in a baby that is exclusively breastfed.

Conversely, pathological jaundice is a cause for concern and indicates an underlying issue. Any jaundice in a baby that arises within the first 24 hours of life is deemed to be pathological and requires urgent investigation.¹

Causes of jaundice in newborns

Jaundice develops when there is a build-up of a pigment called bilirubin in the blood. This is why jaundice is sometimes called hyperbilirubinaemia. Bilirubin is a product of the breakdown of the haem component of haemoglobin, which is found in red blood cells.

There are two forms of bilirubin: unconjugated and conjugated bilirubin. Unconjugated bilirubin is the initial product, but it is conjugated in the liver to become water-soluble so that it can be excreted in bile. Bile is then secreted into the small intestine and passes out of the body via stool and urine.

The relative levels of unconjugated and conjugated bilirubin can indicate the potential cause of the jaundice.

Why does bilirubin build up in the body?

There are three main causes for a build-up of bilirubin: either increased production of bilirubin, poor removal of bilirubin, or other miscellaneous causes (maternal medical conditions, medications).¹

Increased production of bilirubin is attributed to an increased breakdown of red blood cells. A newborn has a higher concentration of red blood cells than an adult, and these cells have a shorter lifespan.¹ If there are more red blood cells, there is more cell breakdown and therefore, a higher level of bilirubin in the blood. This is the case in all newborns, even healthy, full-term babies. However, in newborn jaundice, the bilirubin level is high enough to cause physical manifestations (yellow skin and eyes). This is more likely to occur in preterm babies, unwell babies, or babies with predisposing medical conditions.

High levels of unconjugated bilirubin are associated with both pathological and physiological jaundice.

High levels of conjugated bilirubin indicate cholestasis (impaired flow of bile), leading to poor excretion of bilirubin. This form is always pathological as it is due to an underlying problem such as biliary atresia or idiopathic neonatal hepatitis. This form can last for longer than two to three weeks.¹

Specific types of physiological jaundice

Breastfeeding jaundice (also known as suboptimal intake jaundice):

• Occurs when an exclusively breastfed baby does not receive optimal nutrition, leading to dehydration and increased reabsorption of bilirubin
• Associated with weight loss

Breast milk jaundice:²

• Occurs in exclusively breastfed babies it is thought to be due to substances in breast milk that prevent adequate processing of bilirubin.
• Is a prolonged form of physiological jaundice that can last up to 12 weeks
• No association with weight loss feeding is adequate

Causes of pathological jaundice

Pathological jaundice has several potential causes, including, but not limited to:¹

• Haemolytic disease of the newborn (HND), also known as Rhesus disease
• Glucose-6-phosphate-dehydrogenase deficiency (G6PD)
• ABO incompatibility
• Hereditary spherocytosis
• Neonatal sepsis (infection)
• Haemoglobinopathies (sickle cell anaemia, thalassaemia)

Risk factors

Preterm babies (babies born before 37 weeks gestation) are at an increased risk of developing jaundice because their liver has not fully developed by the time they are born.

Breastfed babies struggling to latch and feed after birth are more prone to developing breastfeeding jaundice. Babies who are exclusively breastfed are at higher risk of developing jaundice (breast milk jaundice).²

Babies with siblings who require treatment for jaundice or who have a family history of red blood cell disorders have an increased risk of developing jaundice.¹

Finally, a baby that obtains a scalp haematoma or significant bruising during delivery can develop jaundice.¹

Signs and symptoms of jaundice in newborns

Jaundice is often first noticeable in the sclerae of an affected baby and becomes more noticeable in a heads-to-toe fashion as bilirubin builds up in the body.² It is also usually more visible on the head, but in babies with darker skin or babies with severe jaundice, the palms of the hands or soles of the feet may appear yellow.

Common signs of jaundice:

• Yellow skin or whites of eyes
• Pale stools
• Darker than usual urine

Additional signs are noticeable when complications occur. These will be detailed in the ‘Complications’ section.

Diagnosis

Babies with jaundice will have a characteristic yellow tinge to their skin or eyes, so a diagnosis can be made based on the newborn’s appearance.

To confirm the jaundice or determine the severity of the condition, a baby will undergo a blood test. The blood test will demonstrate the blood’s bilirubin level, which can be crucial for deciding the most appropriate management for the baby. The blood tests can also identify any underlying causes for pathological jaundice, such as haemoglobinopathies.

Management and treatment for jaundice in newborns

Management is dependent on the bilirubin levels. High levels of unconjugated bilirubin (hyperbilirubinaemia) can be managed with:

Phototherapy³

• The baby is placed under an artificial blue-green light, which converts unconjugated bilirubin into water-soluble substances that can leave the body without having to pass through the liver.
• Babies can still breastfeed and cuddle whilst undergoing phototherapy, but their exposure to the light should be maximised.
• Eye protection is crucial to prevent eye damage

Exchange transfusion⁴

• The baby receives donor blood whilst some of their blood is removed
• Donor blood will contain normal levels of bilirubin, so replacing the baby’s blood with donor blood reduces the level of bilirubin in the blood
• This treatment is used in severe cases of newborn jaundice

Intravenous immunoglobulin¹

• The baby receives immunoglobulin via a vein
• This therapy is most often used when a baby develops jaundice as a consequence of immune haemolysis (immune-mediated destruction of red blood cells—occurs in Rhesus disease or ABO incompatibility)

Complications

Complications resulting from newborn jaundice can happen quickly (acute) or gradually over time (chronic).¹

• Acute bilirubin encephalopathy
• Kernicterus (chronic bilirubin encephalopathy)

These encephalopathies occur when the excess unconjugated bilirubin in the blood crosses the blood-brain barrier and causes brain damage. Acute bilirubin encephalopathy is reversible, but kernicterus is irreversible.

There is an increased risk of developing brain damage when bilirubin levels rise rapidly, or treatment is delayed, and bilirubin accumulates to toxic levels. Therefore, prompt identification of pathological jaundice is vital and can reduce the chance of a baby experiencing lifelong complications because of jaundice.

See a healthcare professional if a baby develops yellowing of the skin, especially if these features are present:

• Poor feeding
• Lethargy (tiredness)
• Increased floppiness or stiffness of the body
• Seizures

Chronic symptoms may include:

• Developmental delays
• Hearing loss
• Movement abnormalities

FAQs

How common is jaundice in newborns?

• In the first week of life, 60% of full-term babies develop jaundice, while 80% of preterm babies develop jaundice in the same time period
• Acute bilirubin encephalopathy occurs in 0.0001% of all births, so is a rare complication of jaundice¹

How can I prevent jaundice in my newborn?

• Maintain regular feeds:
  • If there is difficulty in latching, a midwife should be able to offer further advice and counselling with regards to breastfeeding technique
  • It is important to maintain the baby’s nutrition and hydration levels to prevent breastfeeding jaundice
• Attend all screening appointments during pregnancy and engage with healthcare teams if there is a family history of haemoglobin disorders or red blood cell disorders.

What can I expect if my newborn has jaundice?

• Treatment will depend on the severity of the hyperbilirubinaemia
• However, you can expect your healthcare provider to provide the most appropriate treatment for your baby’s jaundice depending on the cause
• Consider that most cases of newborn jaundice will resolve within two weeks with no longstanding effects, but keep an eye out for the concerning symptoms below

When should I see a doctor?

• If you notice that your baby is developing yellow eyes or skin, it is best to raise the issue to a healthcare professional so that they can assess the jaundice and determine whether further action is required.
• Signs that warrant urgent attention: yellow skin in the presence of poor feeding, irritability, excessive drowsiness, or abnormal movements

Summary

In summary, newborn jaundice is a common phenomenon in babies and is often self-resolving and thus has little cause for concern. However, jaundice in a baby can indicate underlying severe issues which require urgent treatment to prevent long-term neurological complications.