A guide to baby jaundice

• Baby jaundice often appears in the first week due to high bilirubin and usually resolves on its own. 
• Signs include yellow skin or eyes, dark urine, pale stools, poor feeding, or unusual sleepiness/irritability. 
• Seek medical advice if jaundice appears within 24 hours, worsens, or comes with concerning symptoms.

Baby jaundice is a common condition that affects many newborns, especially in the first week of life.  

Jaundice is one of the most common conditions that can affect newborn babies. 

It's estimated 6 out of every 10 babies develop jaundice, including 8 out of 10 babies born prematurely before the 37th week of pregnancy. But only around 1 in 20 babies need treatment. 

Understanding jaundice in babies, recognising the early signs, and knowing when to seek medical advice is crucial for parents to navigate the condition with confidence. 

What is jaundice in babies? 

Baby jaundice occurs when a baby’s skin and the whites of their eyes develop a yellowish tint.  

It happens due to an excess of bilirubin in the blood. This is the substance produced when the body breaks down red blood cells, which carry oxygen around the body. 

By the time a baby is about two weeks old, as their liver matures and becomes better at processing, these levels naturally decrease. 

While mild jaundice is common and usually harmless, it’s important to monitor your baby closely.  

In some cases, high bilirubin levels can lead to complications if not addressed promptly. 

What causes jaundice in babies? 

There are several reasons why babies get jaundice: 

Physiological jaundice  

This is the most common type, affecting many newborns in the first few days of life. It occurs because the baby’s liver is still developing and cannot process bilirubin efficiently. 

Breastfeeding jaundice  

For reasons that are unclear, breastfeeding increases a baby's risk of developing jaundice, which can often persist for a month or longer.  

Premature birth  

Babies born early often have underdeveloped livers, making them more susceptible to jaundice. 

Blood group incompatibility  

If a baby’s blood type is incompatible with their mother’s, it can lead to increased breakdown of red blood cells, causing jaundice. 

Medical conditions  

In rare cases, jaundice may be linked to underlying liver or metabolic problems. 

Understanding what causes jaundice in babies helps parents differentiate between harmless and potentially serious forms. 

Your baby will be examined for signs of jaundice within 72 hours of being born as part of the newborn physical examination. 

Signs to watch for include: 

• Yellowing of the skin, starting from the face and eyes and spreading down to the chest and limbs 
• Dark, yellow urine (a newborn baby's urine should be colourless) 
• Pale-coloured poo (it should be yellow or orange) 
• Poor feeding or lethargy 
• Unusual irritability 

A simple test involves pressing gently on your baby’s forehead or nose. If the skin remains yellow after blanching, it could indicate jaundice. 

Yellowing of the skin can be more difficult to see in brown or black skin, so it might be easier to see on the palms of the hands or the soles of the feet.

Treating newborn jaundice 

Symptoms for jaundice normally pass within 10 to 14 days, though they can occasionally last longer. 

Treatment is usually not needed and only recommended if tests show very high levels of bilirubin in a baby's blood.  

There are two main treatments, carried out in hospital, that help to quickly reduce your baby's bilirubin levels: 

• Phototherapy - a special type of light shines on the skin, which alters the bilirubin into a form that can be more easily broken down by the liver 
• Exchange transfusion - where your baby's blood is replaced with blood from a matching donor 

Jaundice in babies: When to worry 

While mild jaundice is common, parents should seek medical advice if their baby: 

• Develops jaundice within the first 24 hours after birth 
• Has very dark yellow or orange skin 
• Shows signs of poor feeding, excessive sleepiness, or irritability 
• Experiences fever, vomiting, or unusual behaviour 

Prompt medical attention can prevent serious complications. 

Baby jaundice is often a normal and temporary condition but recognising the signs and understanding what causes jaundice means you can detect early and ensure your baby stays healthy.  

Always consult your GP, midwife, or health visitor if you are unsure or notice any worrying symptoms.