Newborn Jaundice & Bilirubin Levels

newborn jaundice and bilirubin - image

Jaundice in newborns is very common, with about 60% of all full-term babies and 80% of preterm babies affected. If you’ve noticed your little one sporting a slightly yellowish tint, don’t fret. This is quite common among newborns and usually isn’t cause for concern. Let’s delve into what jaundice is, why it happens, and how it’s managed.

Estimated reading time: 7 minutes

What is Newborn Jaundice?

Newborn jaundice is a condition that causes the skin and the whites of the eyes to appear yellow. It’s caused by a high level of bilirubin, a yellow pigment produced during the normal breakdown of red blood cells.

Why Do Newborn Babies Get Jaundice?

In all bodies, red blood cells in the blood are constantly breaking down as new ones replace the old. During this process, a yellow chemical called bilirubin is released. This chemical is filtered through the liver and passed from the body in your poop.

When your baby was still in the womb, the placenta did the job of removing the bilirubin while the baby’s liver was still developing. After babies are born, however, their livers have to take over. For some babies, it may take some time to work efficiently. In addition, babies have a higher concentration of red blood cells and these cells are replaced more often, so there’s extra bilirubin in their blood. As this extra bilirubin travels through the intestine, it can be reabsorbed if it isn’t eliminated.

All of these factors, plus more for some babies, make it fairly likely that your baby will have higher than normal levels of bilirubin in her blood, causing jaundice.

How Do I Know if My Baby Has Jaundice?

As bilirubin levels increase, you will start to notice your baby’s skin or eyes getting yellow. As it gets worse, you may see the color spread from the face onto the chest or even lower. This is a sign of more severe jaundice, and they should see their doctor right away.

Sometimes it can be hard to tell if your baby’s skin is more yellow than it should be, especially if they have dark skin. Try checking the pink skin on the inside of the mouth for any yellow coloring. Or press down gently on your baby’s skin with your fingertip. If the skin looks yellow then your baby may have jaundice. The easiest place to see it, though, is usually in the whites of the eyes.

Sometimes babies need to remain in the hospital for an extra few days after birth. But it isn’t always caught before discharge. Most babies leave the hospital within a couple of days after they’re born, but bilirubin levels usually peak between 3 and 7 days old This is why it’s important to bring baby for a checkup a few days after discharge.

Types of Jaundice

Physiological Jaundice (60% of all full term babies) 

Most newborns develop this type of jaundice in the 2- 4 days after birth. It usually doesn’t cause problems and goes away within 2 weeks or so. 

Prematurity Jaundice (80% of all preterm babies) 

Babies who are born before 38 weeks often have an underdeveloped liver that cannot break down bilirubin effectively. Most need to be treated. 

Breastfeeding Jaundice 

Babies who are breastfed are actually more likely to develop jaundice. During the first few days, your baby may not be getting enough milk to eliminate the meconium (which has high levels of bilirubin) effectively. When the bilirubin sits in your baby’s intestines, it is reabsorbed and circulated throughout the body. More feedings (8-12 per day) helps move the bilirubin out of your baby’s body so it doesn’t build up. 

Breast Milk Jaundice 

This type of jaundice shows up in newborns sometime after the first week of life. It turns out that there is something in breastmilk that inhibits the ability of some babies to process bilirubin effectively.

Severe Jaundice

Severe cases of jaundice, if left untreated, can cause nerve and brain damage to your baby. These cases often occur when a baby has a condition affecting the number of red blood cells breaking down in the body. Other factors that make it harder for your baby’s body to remove bilirubin include certain medications, infections and diseases, and low oxygen levels. If you see signs of jaundice, make sure to see a doctor right away. 

What is a Normal Bilirubin Level in a Newborn?

In the first few days after a newborn is delivered, a normal bilirubin level is under 5.2 mg/dL. If baby’s levels are higher than that, he or she will be diagnosed with jaundice.

What Bilirubin Level in a Newborn Requires Treatment?

Remember that while many babies are diagnosed with jaundice, it usually clears up on its own without treatment. Bilirubin levels usually peak at around four days old (in physiological jaundice, the most common kind) and then start to come down. The level that requires treatment varies depending on baby’s age. (And these may not be the exact numbers all doctors use. But a guideline is:

  • Under 24 hours – above 10 mg/dL
  • 24 – 48 hours – above 15 mg/dL
  • 48 – 72 hours – above 18 mg/dL
  • older than 72 hours – above 20 mg/dL

When is it Considered Severe Jauncice?

While many babies will have jaundice, less than two percent of them end up with severe jaundice (called hyperbilirubinemia.) This diagnosis is made if levels are higher than 20 mg/dL.

How is Jaundice Treated?

Mild cases of jaundice will likely resolve on their own within a couple of weeks. If the case is more serious, it may need treatment.

When you take your baby to the doctor, they will likely use a light meter to read initial bilirubin levels. If that reading is high, they will take a small amount of blood to measure bilirubin levels. If the blood test confirms that levels are higher than normal, your doctor will recommend a treatment based on the severity of the jaundice.

Treatments include:

  • Increased Feedings – This is an important step in any case of jaundice, as it helps your baby’s body eliminate the extra bilirubin in their system.
  • Phototherapy – This treatment uses special lights to help reduce the levels of bilirubin. Your baby will be undressed and placed under these lights or a special light-producing blanket for 1 – 2 days. This is usually done at a hospital, but can be used at home for less severe cases.
  • Blood Transfusion– If phototherapy doesn’t work or the jaundice is too severe, your baby may need an exchange transfusion. Some of their blood will be drawn and replaced with new blood.

When Should I Be Concerned About My Newborn’s Jaundice?

If you are concerned or think that your baby may have jaundice, let your doctor know right away. According to the CDC, your baby needs to see a doctor the same day if they are:

  • very yellow or orange
  • hard to wake up or will not sleep
  • not sucking well (breastfeeding or from a bottle)
  • very fussy
  • having too few wet or dirty diapers

and need emergency medical attention if they are:

  • crying inconsolably or with a high pitch
  • arched like a bow
  • stiff, limp, or floppy
  • moving their eyes strangely

Your Role as a Parent

As a parent, your role is to monitor your baby, keep up with regular feedings, and follow any instructions your healthcare provider gives you. Remember, jaundice is typically a temporary condition and one that many families encounter.

Newborn jaundice can be a little alarming at first, but with the right information and care, it can be managed effectively. Always trust your instincts and don’t hesitate to reach out to your healthcare provider with any concerns. You’re doing an incredible job navigating these early days of parenthood. Here’s to healthy, happy babies and empowered, informed parents!


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  2. Gavin, M. (April 2019). Jaundice in Newborns. KidsHealth.
  3. Simkin, P., Whalley, J., Durham, J. & Bolding, A. (2016). Pregnancy, Childbirth, and the Newborn The Complete Guide. Meadowbrook Press. 
  4. Mitra, S., & Rennie, J. (2017). Neonatal jaundice: aetiology, diagnosis and treatment. British Journal of Hospital Medicine, 78(12), 699-704.
  5. Newborn jaundice: MedlinePlus Medical Encyclopedia. MedlinePlus.
  6. Breastfeeding: Jaundice. (2019, Dec). Centers for Disease Control and Prevention.,thus%20reducing%20the%20elevated%20bilirubin.
  7. Jaundice & Kernicterus: What are Jaundice & Kernicterus? (2019 Nov). Centers for Disease Control and Prevention.

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Meet Katie Griffin

I’m a registered nurse, Lamaze certified childbirth educator, and the mother of 7. I help women realize their dream of a natural, intimate, and empowering hospital birth.

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Jaundice in newborns is very common, with about 60% of all full-term babies and 80% of preterm babies affected. If you’ve noticed your little one sporting a slightly yellowish tint,