Newborn Jaundice: What Parents Should Know

You have just brought your baby home. You are watching their every breath, every twitch, every colour shift. Then, around day two or three, you notice their skin looks a little yellow. Maybe their eyes seem tinged with it too. Your stomach drops.

Take a breath. What you are most likely seeing is newborn jaundice, and it is one of the most common conditions in the first week of life. Around 60% of full-term newborns and 80% of premature babies develop some degree of jaundice in their first days. Most cases resolve on their own without any treatment at all.

That said, jaundice does need to be taken seriously. In a small number of cases, it can become severe and require prompt medical attention. This guide will walk you through exactly what is happening in your baby's body, how to spot the signs that matter, what treatment looks like, and when it is time to call your doctor.

What Is Newborn Jaundice?

Jaundice is the yellow colouring of the skin and the whites of the eyes. It happens when there is too much bilirubin in the blood, a condition called hyperbilirubinemia. Bilirubin is a yellow pigment produced when red blood cells break down. Normally, the liver processes bilirubin and the body excretes it through stool.

In newborns, this system is not yet fully up to speed. Babies are born with a high number of red blood cells, and their immature livers simply cannot keep pace with the rate at which those cells break down. Bilirubin builds up in the blood and deposits in the skin, causing that yellow tinge.

This is called physiological jaundice, the ordinary, expected kind. It typically appears on day two or three, peaks around day four or five, and clears by the end of the second week for full-term babies.

Other Types of Newborn Jaundice

While physiological jaundice is the most common, it is helpful to know there are a few other types:

• Breastfeeding jaundice: This occurs in the first week when a baby is not feeding frequently enough or is having difficulty latching. Less milk means less stool, which means less bilirubin leaving the body. It is sometimes called breastfeeding failure jaundice, though that term can feel unfairly loaded. The fix is almost always more frequent, effective feeding.
• Breast milk jaundice: Different from breastfeeding jaundice, this type appears after the first week and can last several weeks. It is thought to be caused by a substance in breast milk that interferes with bilirubin processing. It is generally benign, but your doctor will monitor it closely.
• Pathological jaundice: This rarer form appears within the first 24 hours and is caused by an underlying condition such as blood type incompatibility between mother and baby (Rh or ABO incompatibility), a liver disorder, infection, or an enzyme deficiency. It requires prompt investigation and treatment.

"Jaundice in the first 24 hours of life is never physiological and always warrants urgent evaluation. Parents should know that the timing of jaundice is just as important as the degree of yellowing."

Dr. Vinod Bhutani, MD, Professor of Pediatrics, Stanford University School of Medicine

Spotting the Signs: How to Check Your Baby

Jaundice is usually visible to the naked eye, but lighting matters enormously. Artificial indoor light can mask yellowing. The best way to check is to press gently on your baby's forehead or nose in natural daylight. When you release the pressure, the skin underneath should look white or pink. If it looks yellow, that is a sign worth noting.

Jaundice typically spreads from head to toe as bilirubin levels rise. So yellowing in just the face is usually a lower level; yellowing spreading to the chest, abdomen, arms, and legs indicates higher levels that need checking.

Other signs to watch for include:

• Yellowing of the whites of the eyes
• Dark, concentrated urine (newborn urine should be pale yellow or almost clear)
• Pale, chalky, or white stools (stools should be yellow or green-yellow by day four or five)
• Difficulty waking for feeds or unusual drowsiness
• High-pitched or unusual crying
• Poor feeding or weak sucking

The last few signs, particularly extreme sleepiness and feeding difficulties, can indicate bilirubin levels are becoming elevated enough to affect brain function. This is rare, but it is the scenario doctors want to catch early.

How Is Jaundice Diagnosed?

Before you leave the hospital, your care team will assess your baby for jaundice visually and may use a transcutaneous bilirubinometer, a device that measures bilirubin levels through the skin with a simple painless scan on the forehead. If levels appear elevated, a blood test (a small heel prick) will be used to get a precise reading.

Your baby's bilirubin level is always interpreted alongside their age in hours and any risk factors they have. A level that is perfectly fine at 72 hours might be a concern at 24 hours. This is why the American Academy of Pediatrics recommends that all newborns be assessed before hospital discharge and have a follow-up appointment within 48 hours if they are discharged before 72 hours of age.

Risk Factors That Increase the Chance of Significant Jaundice

Certain factors mean a baby is more likely to develop higher bilirubin levels. These include:

• Prematurity (born before 37 weeks)
• A sibling who had jaundice requiring treatment
• Bruising at birth, including from a vacuum or forceps delivery
• Blood type incompatibility with the mother
• East Asian or Mediterranean heritage (higher rates of certain enzyme deficiencies)
• Difficulty establishing breastfeeding in the first days
• Significant weight loss after birth (more than 8-10% of birth weight)

Treatment: What Actually Helps

Frequent Feeding

For mild to moderate jaundice, the single most effective thing you can do is feed your baby frequently and effectively. Bilirubin leaves the body through stool. The more milk your baby takes in, the more stool they produce, and the faster bilirubin clears. Aim for 8-12 feeds in 24 hours in the newborn period.

If you are breastfeeding and your baby is very sleepy or not latching well, ask for support from a lactation consultant as soon as possible. In some cases, supplementing with expressed breast milk or formula is recommended by the medical team to ensure adequate intake.

"Frequent, effective feeding is genuinely therapeutic in early jaundice. It is not just reassurance. Every feed is helping to move bilirubin through the system. Supporting parents with feeding in the first days is one of the most impactful things a care team can do."

Dr. Ann Kellams, MD, IBCLC, Professor of Pediatrics, University of Virginia School of Medicine

Phototherapy

When bilirubin reaches a level that requires treatment, phototherapy (light therapy) is the standard approach. Blue-spectrum light breaks down bilirubin in the skin into a form the body can excrete without needing the liver to process it.

In hospital, this involves placing your baby under a special light source in a warm cot, with their eyes protected by small shields. Phototherapy is highly effective and safe. Most babies need it for 24-48 hours before bilirubin drops to a safe level.

For milder cases that do not quite meet the threshold for hospital phototherapy, some doctors use a biliblanket, a fibre-optic blanket that wraps around the baby and can be used at home while monitoring continues.

Exchange Transfusion

This is rare and is reserved for very high bilirubin levels that are not responding to intensive phototherapy. It involves slowly replacing the baby's blood with donor blood to rapidly lower bilirubin. It is an intensive procedure done in a neonatal unit, but outcomes are excellent when it is performed before bilirubin reaches dangerous levels.

When to Call Your Doctor or Seek Urgent Help

Trust your instincts. If something seems off, call. Specifically, contact your doctor or go to the emergency department if your baby:

• Develops yellow skin in the first 24 hours of life
• Has yellowing spreading rapidly to the abdomen, arms, and legs
• Becomes extremely difficult to wake for feeds
• Has high-pitched, inconsolable crying
• Is arching their back
• Has very dark urine or white/clay-coloured stools
• Was discharged early from hospital and you have not yet had a follow-up visit

Untreated severe hyperbilirubinemia can, in rare cases, cause a condition called kernicterus, where bilirubin deposits in the brain. It is almost entirely preventable with proper monitoring and timely treatment. This is why newborn jaundice checks are built into standard postnatal care.

Supporting Yourself Through This

Watching your newborn under lights, in a hospital cot, in those first fragile days, is one of the hardest things a new parent can experience. Even though jaundice is common and treatable, that does not make sitting beside a biliblanket any less emotionally draining.

A few things that can help:

• Stay informed but do not doom-scroll. Ask your care team to explain your baby's specific numbers and what the target is. Having a concrete goal helps.
• Keep feeding as normal as possible. You can usually continue breastfeeding during phototherapy. The breaks for feeding are not just necessary, they are therapeutic.
• Ask for support. Whether that is a lactation consultant, a postnatal nurse, or your partner sitting with you, you do not need to navigate this alone.
• Know it will pass. The vast majority of babies who need phototherapy are home within days with bilirubin levels well within the normal range.