Newborn Jaundice: What to Expect and When to Call Your Pediatrician

You just had your baby, you are running on almost no sleep, and now the nurses are talking about bilirubin levels and checking your little one's skin color. It can feel alarming when you hear the word "jaundice," especially in those tender first days. But here is something worth knowing right away: newborn jaundice is incredibly common. Most babies develop some degree of it, and for the vast majority, it resolves on its own without any lasting effects.

That said, it is absolutely worth understanding what jaundice is, how to spot it, and what signs should prompt a call to your pediatrician. Knowing what to watch for gives you peace of mind, and it helps you feel like an informed partner in your baby's care rather than a worried bystander.

Here is a plain-language look at newborn jaundice, what to expect, and how to navigate those first few weeks with a little more confidence.

What Is Newborn Jaundice?

Newborn jaundice is a yellowing of the skin and eyes caused by a buildup of bilirubin in the blood. Bilirubin is a yellow pigment that forms when red blood cells break down. In adults and older children, the liver processes bilirubin efficiently and passes it out of the body. In newborns, the liver is still getting up to speed, so bilirubin can temporarily accumulate faster than it can be cleared.

According to the American Academy of Pediatrics (AAP), jaundice affects somewhere between 60 and 80 percent of newborns in the first week of life. So if your baby has it, you are in very good company. The medical term for this normal, expected type is "physiological jaundice," and it is simply the body adjusting to life outside the womb.

Why Does It Happen?

Before birth, your baby had a higher concentration of red blood cells to carry oxygen through the placenta. After birth, those extra red blood cells break down quickly. A newborn's liver, which has not yet had much practice, can get a little behind on processing all that bilirubin. The result is that bilirubin builds up in the blood and eventually shows in the skin and eyes as that characteristic yellow color.

Feeding plays a big role in how quickly bilirubin clears. Bilirubin leaves the body through stool, so the more your baby eats and poops in the first days, the faster bilirubin can be flushed out. This is one reason hospital teams and pediatricians focus so much on making sure newborns are feeding well from the very beginning. If you are curious about typical diaper output in those first days, our guide on how many wet diapers a newborn should have gives a helpful breakdown by day.

Types of Newborn Jaundice

Not all newborn jaundice is the same, and understanding the differences can help you make sense of what your care team is monitoring.

Physiological jaundice and breastfeeding jaundice are both common and usually manageable. Breast milk jaundice can seem worrying because it lingers longer, but it is generally mild and does not typically require stopping breastfeeding. Pathological jaundice is less common but requires prompt evaluation because it can point to an underlying condition that needs treatment.

What Jaundice Looks Like

The yellow color of jaundice tends to start at the face, then travel downward to the chest, belly, arms, and finally the legs and feet as bilirubin levels rise. One rough way to assess this at home is to press gently on your baby's forehead or nose tip with a clean finger, then release. If the skin underneath looks yellow rather than pale or pink, that can be a sign of jaundice. Keep in mind this works best in natural daylight, as artificial lighting can make it harder to see accurately.

The whites of the eyes can also appear yellow, which is a useful check especially in babies with darker skin tones where the yellowing of the skin may be harder to see. If you are unsure what you are looking at, always check in with your pediatrician. It is always okay to call with questions, no matter how small they might seem.

Typical Timeline

For most full-term babies with physiological jaundice, bilirubin levels tend to peak somewhere around day 3 to 5. After that, levels usually start to come down gradually. By the end of the first week, most babies are well on their way to clearing it. Full resolution typically happens within 1 to 2 weeks for formula-fed babies, and sometimes a little longer for breastfed babies.

Premature babies often take longer because their livers are even less mature. They may require closer monitoring and sometimes phototherapy even at lower bilirubin levels than a full-term baby would. If your baby arrived early, your care team will have specific guidelines tailored to your baby's gestational age.

If your baby's jaundice is not improving by the end of the second week, or if it comes back after seeming to clear, that is worth a call to your pediatrician. Prolonged or recurring jaundice can sometimes point to an underlying issue worth investigating.

How Jaundice Is Treated

For mild jaundice, the main "treatment" is simply frequent feeding. The more your baby eats, the more they poop, and the faster bilirubin clears. Your care team may ask you to feed every 2 to 3 hours and may even wake your baby to feed during the early days if bilirubin is on the higher end of normal. If you are finding it hard to establish a feeding rhythm, our guide on baby feeding schedules by age may give you some helpful context on what newborn feeding typically looks like.

When bilirubin levels reach a threshold that your pediatrician determines needs treatment, phototherapy is the most common approach. This involves placing your baby under special blue-spectrum lights that help break down bilirubin in the skin. Hospital phototherapy can be done with a lamp overhead, or sometimes with a blanket-style device called a biliblanket. In some cases, babies can receive phototherapy at home under medical supervision, though many situations require a hospital stay for closer monitoring.

In rare situations where bilirubin levels are very high despite phototherapy, an exchange transfusion may be needed. This is uncommon, but it is why early identification and treatment of jaundice matters. Most babies who are monitored appropriately never reach that point.

Feeding and Jaundice

The relationship between feeding and jaundice is a topic many parents find confusing, especially if they are breastfeeding. There are actually two different jaundice patterns related to breastfeeding, and they are often mixed up.

Breastfeeding jaundice happens in the first week and is linked to a baby not getting enough milk, which slows down the stool output that clears bilirubin. The fix is usually more frequent feeding, better latch help, or supplementation if milk supply is still being established. A lactation consultant can be a real lifeline here. Feeding your baby more frequently is almost always the right direction, and many parents find that learning to read newborn feeding cues helps them offer the breast or bottle more responsively.

Breast milk jaundice, on the other hand, happens after the first week in some breastfed babies and is thought to be related to substances in breast milk that affect how bilirubin is processed. It tends to be mild and usually does not require stopping breastfeeding. Your pediatrician will guide you on whether any changes to your feeding approach are needed based on your baby's specific bilirubin levels.

One of the most important things to watch alongside feeding is diaper output. Wet and dirty diapers are a good sign that your baby is getting enough and that bilirubin has a path out of the body. If you are concerned about whether your baby is staying hydrated, our article on signs of dehydration in babies covers what to look for.

When to Call Your Pediatrician

Newborn jaundice is common and usually mild, but there are certain signs that should prompt you to reach out to your baby's doctor without waiting. Trust your instincts. You know your baby, and it is always better to make an extra call than to wonder.

Reach out to your pediatrician promptly if the yellow color is spreading downward to your baby's belly, arms, or legs; if the whites of the eyes look yellow; if your baby seems unusually sleepy and is hard to wake for feedings; if your baby is not feeding well or seems uninterested in eating; if the yellow color appears within the first 24 hours of life (this is always worth an immediate call); or if the jaundice is not fading or seems to be getting worse after the first week. Also check in with your pediatrician any time jaundice lingers past two weeks in a full-term baby or past three weeks in a breastfed baby.

Jaundice that goes untreated at very high levels can cause a rare but serious condition called kernicterus, which is why the medical community takes bilirubin monitoring seriously. The good news is that when jaundice is caught and managed appropriately, complications are rare. Regular follow-up appointments in the first week or two are your best protection.