Jaundice in babies

Jaundice is a very common condition in babies, affecting around six in 10 newborns. In most cases, it is not dangerous or harmful but causes yellowing of the whites of the eyes and the skin. This is in contrast to jaundice in adults, which is rare and is a sign of an underlying health condition that needs treatment. 

Here, we will explore jaundice symptoms in babies, when to worry about jaundice in babies, as well as potential complications and how it is treated.

Why do babies get jaundice?

Jaundice occurs due to a build-up of a yellow pigment called bilirubin. Bilirubin is produced when red blood cells are broken down. 

In adults, a red blood cell has a lifespan of around 120 days before it is broken down. In newborns, the average lifespan of a red blood cell is 60–90 days and in preterm babies, it’s 35–50 days. As babies have more red blood cells than adults, this means more blood cells are broken down more frequently in newborns. 

While in the womb, the waste products of red blood cells being broken down are removed by the mother’s placenta. After birth, the baby’s own body has to remove these waste products. This occurs via the liver. 

However, at birth, a baby’s liver is not fully developed. This means it’s not as effective at removing bilirubin, so it can build up and cause jaundice. This is called physiological jaundice.

What else causes jaundice in babies?

While jaundice in most babies is part of their development and will resolve on its own, in some cases, it’s caused by an underlying health condition. This is called pathological jaundice. 

Pathological jaundice can be caused by:

• A urinary tract infection (UTI) 
• A blood infection (sepsis)
• Blockage of a bile duct (biliary atresia) — these transport bile from the liver to the gallbladder where it’s stored; a blocked bile duct can cause bile to build up in the liver and leak into the blood 
• Inherited diseases, namely: 
• Crigler–Najjar syndrome — this interferes with the levels of an enzyme that helps process bilirubin
• Glucose-6-phosphate dehydrogenase deficiency — this causes red blood cells to be broken down prematurely 
• Hypothyroidism — this occurs when the thyroid gland does not produce enough thyroid hormone
• Rhesus disease – this occurs when the mother's blood is incompatible with the baby's blood due to a protein on the surface of the baby's red blood cells called rhesus that is absent from the mother's red blood cells

Jaundice and breastfeeding

Breastfeeding can cause jaundice in newborns to last longer than two weeks and as long as 12 weeks. The reason for this is not entirely clear. However, it’s thought that as breast milk changes from being colostrum, which is produced during the first two to five days, to mature milk after around two weeks, enzymes in the mature milk reduce the ability of the baby’s liver to remove bilirubin. 

However, the benefits of breastfeeding are greater than the drawback of temporarily prolonging jaundice. Consequently, most mothers are advised to continue breastfeeding. Moreover, increasing the frequency of breastfeeding can help your baby remove bilirubin faster by increasing their hydration and nutrition. 

Jaundice symptoms in babies

In a full-term newborn, jaundice usually develops after two days and resolves on its own after two weeks. In a preterm baby, jaundice usually develops after five to seven days and resolves on its own after three weeks. 

Jaundice causes the skin to appear yellow, although this can be harder to see on darker skin tones. Yellowing of the skin is usually more obvious on the face and head. 

If you are not certain whether your baby has jaundice, try pressing a finger gently on their nose or forehead in good lighting, ideally, natural daylight. On removing your finger, the skin will appear momentarily yellow if they have jaundice or slightly paler than their usual skin tone if they do not have jaundice. 

Yellowing also occurs in the white of the eyes, soles of the feet, palms of the hand, and inside the mouth, specifically the gums.

Other symptoms include: 

• Dark yellow urine — healthy urine in a newborn should be colourless
• Pale stools — healthy stools in a newborn should be yellow or orange
• Poor feeding — either feeding less often, in smaller amounts or showing no interest in feeding
• Sleepiness — signs of sleepiness include your baby being floppy or fussy due to tiredness 

When to seek help for jaundice

All babies born in the UK are checked for jaundice within 72 hours of birth during their newborn physical examination. If your baby develops symptoms of jaundice after this, contact your GP, midwife or health visitor as soon as possible. 

They will examine your baby and monitor them until their jaundice clears. 

Diagnosing jaundice in babies

In most cases, jaundice in babies is diagnosed through a physical examination and bilirubin test. 

A healthcare professional will look for signs of yellowing of your baby’s skin, whites of their eyes and gums. They will also check the colour of their urine and stools. 

In most cases, bilirubin levels are measured using a handheld device called a bilirubinometer. By shining a light onto your baby's skin and detecting how much light is reflected back, a bilirubinometer can measure bilirubin levels in their blood.

If the measurement is very high or your baby developed jaundice within 24 hours of birth, your doctor may also recommend a heel-prick blood test to measure bilirubin levels. 

Your baby's heels will be pricked with a needle. A few drops of blood will be gently squeezed out and collected into a thin glass capillary tube. The blood will be tested in a lab for bilirubin levels. 

If your baby’s jaundice persists for more than two weeks, they may need further tests to rule out an underlying health condition. This will usually involve blood tests to check for infections, reduced levels of certain enzymes and antibodies that suggest an incompatibility between the baby's and mother’s blood types. 

Jaundice treatment in babies

Physiological jaundice doesn’t usually need treatment and will get better on its own in two to three weeks. 

If your baby’s jaundice persists for too long or their bilirubin levels are very high, treatment in hospital will be recommended. There are two main treatments: phototherapy and an exchange transfer.

Phototherapy

Your baby will be placed in a cot or incubator, their eyes will be covered and they will be exposed to a special type of light that helps their liver remove bilirubin. There will be breaks in their treatment so you can breastfeed your baby and hold them.

If standard phototherapy is not effective, they will receive intensified phototherapy where they will be exposed to more light or will additionally be covered with a light blanket. No breaks are possible with intensified phototherapy. Your baby will, therefore, be fed bottle milk or expressed breast milk. 

During phototherapy, your baby’s temperature will be monitored, as well as signs of dehydration. If they become dehydrated, they will be given fluids via a tube inserted into a vein (intravenous fluids). 

Their bilirubin levels will be measured via a heel-prick blood test every four to six hours until their bilirubin levels start to decrease. After this point, their bilirubin levels will be checked every six to 12 hours. 

In most cases, it takes one to two days for bilirubin to reduce to a safe level. At this point, phototherapy can be stopped and you and your baby can return home. 

Exchange transfer

If phototherapy is not effective at treating your baby’s jaundice or they have very high bilirubin levels when diagnosed, your doctor will recommend a complete blood transfusion called an exchange transfer. 

A small tube will be placed into a vein in your baby’s arm, leg or umbilical cord. Over several hours all of their blood will be removed and replaced with donor blood. This will rapidly reduce their bilirubin levels, which will be tested after two hours.

Other treatments for jaundice

Pathological jaundice, that is, jaundice caused by an underlying health condition, needs specific treatment depending on the cause. For example, antibiotics for an infection, antibody treatment for Rhesus disease or surgery for a blocked bile duct.  

Complications of jaundice in babies

If jaundice in a baby persists for too long and is left untreated, it can lead to a rare but serious complication called kernicterus. 

Kernicterus occurs when high levels of bilirubin damage the brain, central nervous system and/or spinal cord. 

Symptoms of kernicterus include: 

• Apnoea, that is, temporary pauses in your baby’s breathing
• Being fussy or irritable
• High-pitched cries
• No startle reflex — this is when your baby extends and retracts their arms and legs in response to a sudden movement or loud noise
• Poor feeding
• Seizures and muscle spasms — this occurs as kernicterus progresses and can cause arching of the back

Kernicterus needs urgent treatment with an exchange transfusion, where all of the baby's blood is replaced with donor blood. 

Other causes of yellow skin

The vast majority of cases of yellowing skin in newborns are due to jaundice. However, in older babies who are consuming foods other than breast milk, yellow skin can be due to carotenemia. 

Carotenemia is caused by excessively high levels of the protein beta-carotene in the blood. This is due to following a diet high in carotene-rich foods for a prolonged period of time. Carotene-rich foods include carrots, sweet potatoes and squash. 

Carotenemia is not harmful and does not need treatment. If carotene-rich foods are reduced, carotenemia will go away on its own.