If you've noticed a yellow tinge to your newborn's skin or eyes in the days after birth, you're not alone. Newborn jaundice is one of the most common conditions in the early postnatal period, and for most babies, it resolves on its own without any lasting effect. Still, as a new parent, it's natural to feel unsettled by any change in your baby's appearance, especially in those first precious weeks.
This guide walks through what newborn jaundice actually is, why it happens, and the signs that indicate it's time to speak with your health practitioner.
What Is Newborn Jaundice?
Newborn jaundice occurs when there's a build-up of bilirubin in a baby's blood. Bilirubin is a yellow pigment produced when red blood cells break down, a normal process that happens throughout life. In adults, the liver processes and clears bilirubin efficiently. In newborns, the liver is still maturing, so it can take a little longer to keep up with bilirubin production, leading to that characteristic yellow colouring of the skin and eyes.
What Percentage of Newborns Get Jaundice?
Jaundice is remarkably common. Around 60 percent of full-term babies and up to 80 percent of premature babies will develop some degree of jaundice in their first week of life. Most cases are mild and considered a normal part of a newborn's transition to life outside the womb.
Causes of Newborn Jaundice
There are several reasons a baby might develop jaundice, and understanding the type can help explain how it's likely to progress.
Physiological Jaundice in Newborns
This is the most common form and what most parents are referring to when they mention newborn jaundice. Physiological jaundice typically appears on day two or three of life and is simply a result of the baby's immature liver catching up with the natural breakdown of red blood cells. It usually peaks around day four or five and starts to improve on its own from there.
Breastfeeding Jaundice
Breastfeeding jaundice tends to appear in the first week of life and is usually linked to a baby not yet feeding frequently or effectively enough, which can slow the clearance of bilirubin through the bowel. This is different to breast milk jaundice, which appears later, often from around one week of age, and is thought to relate to substances in breast milk that affect how bilirubin is processed. Breast milk jaundice can last several weeks but is generally harmless, and stopping breastfeeding is rarely recommended. If your midwife or GP raises concerns about feeding frequency or milk transfer, it's worth exploring this with a lactation consultant to support both your supply and your baby's feeding.
Other Causes
Less commonly, jaundice can be linked to blood group incompatibilities between mother and baby, bruising sustained during birth, infection, or underlying liver conditions. These causes are far less frequent but are part of why ongoing monitoring in the newborn period matters.
Newborn Jaundice Symptoms
Signs of jaundice in babies to look out for include:
- Yellowing of the skin, usually starting at the face and moving down the body as levels rise
- A yellow tinge to the whites of the eyes
- In babies with darker skin tones, yellowing may be easier to spot on the gums, the whites of the eyes, or the soles of the feet
- Unusually sleepy or difficult to wake for feeds
- Fewer wet or dirty nappies than expected
Checking your baby in natural daylight, rather than under artificial lighting, gives the clearest picture of any newborn skin colour changes.
Newborn Jaundice Bilirubin Levels Chart
Health professionals measure bilirubin either with a light-based skin sensor or a blood test, then plot the result against your baby's age in hours on a standardised chart. This chart accounts for the fact that a "normal" bilirubin level at twelve hours old looks quite different to a normal level at four days old. Your midwife, GP or paediatrician will use this chart to determine whether your baby's levels sit within an expected range or require closer attention, so try not to be alarmed by a raw number without that context.
When Is Newborn Jaundice Serious?
For most babies, jaundice is mild and temporary. However, there are situations where it becomes important to seek prompt medical advice.
When Should I Worry About My Baby's Jaundice?
Contact your midwife, GP or hospital promptly if you notice:
- Jaundice appearing within the first 24 hours of life
- Yellowing that spreads to your baby's arms, legs or abdomen
- Your baby seeming floppy, lethargic or very difficult to rouse
- A high-pitched cry, poor feeding, or a fever
- Pale, chalky stools or dark urine
- Jaundice that persists beyond two to three weeks in a full-term baby
Newborn Jaundice vs Liver Problems
Occasionally, prolonged jaundice can point to an underlying liver condition, such as biliary atresia, rather than the typical physiological pattern. This is uncommon, but it's precisely why pale stools and dark urine are considered important red flags. Your baby's postnatal check-ups are designed to pick up on these signs early, which is why attending every scheduled check matters, even when everything seems well.
How Is Newborn Jaundice Treated?
Newborn Jaundice Treatment
Mild jaundice often needs no treatment beyond frequent feeding, which helps clear bilirubin through your baby's digestive system. Feeding your baby regularly, whether by breast or bottle, supports this natural process.
For higher bilirubin levels, phototherapy for jaundice is the standard and well-established treatment. This involves placing your baby under a special blue light, which changes the bilirubin in the skin into a form the body can eliminate more easily. Phototherapy is generally straightforward, well tolerated, and your baby can usually still be held and fed during breaks in treatment. In rare, more severe cases, further medical intervention may be recommended by your care team.
How Long Does Newborn Jaundice Last?
Physiological jaundice typically resolves within one to two weeks. Breast milk jaundice can linger longer, sometimes up to three to twelve weeks, but usually without any impact on your baby's health or feeding. If jaundice persists beyond three weeks, it's worth having your baby reviewed to rule out any less common causes.
Supporting Yourself Through the Early Postnatal Period
Watching for changes in your newborn while you're also recovering from birth and establishing feeding is a lot to hold. Attending your postnatal check-ups gives you a reliable checkpoint for both your baby's progress and your own recovery, including support for breastfeeding if that's part of your journey. If you ever feel unsure, trust that instinct and reach out to your midwife, GP or child health nurse. Reassurance from someone who can properly assess your baby is always worth seeking, and there's no such thing as an unnecessary question in those early weeks.
This article is general information and is not a substitute for individual medical advice. If you are concerned about your baby's health, please speak with your doctor, midwife or child health nurse.
